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Prevalence of neurological disorders in French bulldog: A retrospective study of 343 cases (2002-2016)


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Background French Bulldog (FB) has significantly gained in popularity over the last few years, and seems to be frequently affected by various neurological conditions. The purpose of this retrospective study was to report the prevalences of neurological diseases in a large population of FB, presented with neurological signs between 2002 and 2016, and for which a definitive diagnosis was established. A secondary objective was to identify epidemiological characteristics regarding specific diseases in this singular breed. Results During the study period, 533 FBs were presented for neurological signs, representing 18.7% of all admitted FBs (N = 2846). In total, 343 FBs with definitive diagnosis were included in this descriptive epidemiological study. Hansen type I intervertebral disk herniation (IVDH) was by far the most common neurological disorder (45.5% of all cases). The IVDH location was cervical in 39.8%, and thoracolumbar in 60.2% of cases. The median ages for cervical and thoracolumbar IVDH were 4.2 and 4 years, respectively. C3-C4 was the most commonly affected disk (57.8% of cervical IDVH) all locations combined. Spinal arachnoid diverticulum (SAD) was detected in 25 FBs, representing the second most common myelopathy (11.3%). A concurrent spinal abnormality was identified in 64.0% of SAD cases. Brain tumours represented 36.8% of encephalopathies, with glioma (confirmed or suspected) being the most common. Meningoencephalitis of unknown origin (MUO) represented 25.0% of brain disorders, females less than 5.5 years being more likely to be affected. Aside from central nervous system conditions, otitis interna associated with peripheral vestibular signs and bilateral congenital deafness (associated with white coat) were also common. Conclusions The findings of this study suggest that FB seems to be prone to several neurological diseases. IVDH is clearly predominant in FB and cervical location seems more represented than in other breeds. FBs affected by IVDH tend to be younger than previously described, either for both cervical and thoracolumbar locations. Thoracic SAD was the second most common myelopathy, with a concurrent spinal anomaly identified in two thirds of the cases. MUO was more likely to affect young to middle-aged females. These findings could be of interest for owners, breeders, practicing veterinarians and insurance companies.
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R E S E A R C H A R T I C L E Open Access
Prevalence of neurological disorders in
French bulldog: a retrospective study of
343 cases (20022016)
Vincent Mayousse
, Loïc Desquilbet
, Aurélien Jeandel
and Stéphane Blot
Background: French Bulldog (FB) has significantly gained in popularity over the last few years, and seems to be
frequently affected by various neurological conditions. The purpose of this retrospective study was to report the
prevalences of neurological diseases in a large population of FB, presented with neurological signs between 2002
and 2016, and for which a definitive diagnosis was established. A secondary objective was to identify epidemiological
characteristics regarding specific diseases in this singular breed.
Results: During the study period, 533 FBs were presented for neurological signs, representing 18.7% of
all admitted FBs (N= 2846). In total, 343 FBs with definitive diagnosis were included in this descriptive
epidemiological study. Hansen type I intervertebral disk herniation (IVDH) was by far the most common
neurological disorder (45.5% of all cases). The IVDH location was cervical in 39.8%, and thoracolumbar in
60.2% of cases. The median ages for cervical and thoracolumbar IVDH were 4.2 and 4 years, respectively.
C3-C4 was the most commonly affected disk (57.8% of cervical IDVH) all locations combined. Spinal
arachnoid diverticulum (SAD) was detected in 25 FBs, representing the second most common myelopathy
(11.3%). A concurrent spinal abnormality was identified in 64.0% of SAD cases. Brain tumours represented
36.8% of encephalopathies, with glioma (confirmed or suspected) being the most common. Meningoencephalitis of
unknown origin (MUO) represented 25.0% of brain disorders, females less than 5.5 years being more likely to be
affected. Aside from central nervous system conditions, otitis interna associated with peripheral vestibular signs and
bilateral congenital deafness (associated with white coat) were also common.
Conclusions: The findings of this study suggest that FB seems to be prone to several neurological diseases. IVDH is
clearly predominant in FB and cervical location seems more represented than in other breeds. FBs affected by IVDH
tend to be younger than previously described, either for both cervical and thoracolumbar locations. Thoracic SAD was
the second most common myelopathy, with a concurrent spinal anomaly identified in two thirds of the cases. MUO
was more likely to affect young to middle-aged females. These findings could be of interest for owners, breeders,
practicing veterinarians and insurance companies.
Keywords: Canine, Neurology, Epidemiology, Intervertebral disk disease, Referral centre, France
* Correspondence:
Université Paris-Est, Ecole Nationale Vétérinaire dAlfort (EnvA), Unité de
Neurologie, 7 avenue du général de Gaulle, 94700 Maisons-Alfort, France
Inserm, IMRB U955-E10, 8 rue du général Sarrail, 94000 Créteil, France
Full list of author information is available at the end of the article
© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (, which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
( applies to the data made available in this article, unless otherwise stated.
Mayousse et al. BMC Veterinary Research (2017) 13:212
DOI 10.1186/s12917-017-1132-2
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
The French Bulldog (FB) is a canine breed originating
from France. The numbers of FBs have markedly
increased in recent decades. In Europe, FB has signifi-
cantly gained in popularity over the last few years. For
example, annual registrations of FBs have quadrupled
over the past 15 years in France [1], and in the United
Kingdom, 14,607 new registrations to the Kennel Club
were recorded in 2015 versus 526 in 2006 [2]. In North
America, FB was the 6th most popular breed in the
United States in 2014 [3], and the 9th most popular
breed in Canada in 2015 [4]. Due to the brachycephalic
and chondrodystrophic body conformation resulting
from selective inbreeding, a high prevalence of vari-
ous diseases has been described in this breed, includ-
ing several neurological conditions [5]. These include
not only myelopathies such as compressive vertebral
malformations [6], spinal arachnoid diverticula [7]
and intervertebral disc disease [8], but also encephal-
opathies such as brain tumours [9] or non-infectious
encephalitides [10]. To the authorsknowledge, no
study has yet reported the prevalences and distribu-
tions of different neurological disorders in FB or has
described a specific neurological condition in this
emerging breed. The primary objective of this
epidemiological study was therefore to report the
prevalences of different neurological conditions in a
large population of FBs presented for neurological
signs at a major referral centre. A secondary objective
was to identify epidemiological characteristics regar-
ding specific diseases in this singular breed.
Case selection
Case records of all French bulldogs presented for neuro-
logical signs (including spinal pain) at our institution
between January 1st, 2002 and January 1st, 2016 were
retrospectively reviewed. Dogs were included if they met
all the following inclusion criteria: (i) neurological clin-
ical signs, including isolated spinal pain, (ii) complete
available records and (iii) a definitive etiological diagno-
sis. The only exception was the inclusion of young dogs
presented for an auditory function screening, as several
animals were asymptomatic. Dogs that did not present
actual neurological clinical signs or signs mimicking a
neurological condition but related to another cause (e.g.
orthopaedic or ophthalmic conditions) were otherwise
excluded. Similarly, animals with only a neuroanatomical
diagnosis (e.g. T2-L2 myelopathy,orcauda equina
syndrome) were not included in the study.
Neurological diseases classification
When a dog was presented at our institution two times
or more for neurological conditions, only the first one
for which the dog was presented was taken into account.
Similarly, when two concomitant neurological diseases
were diagnosed at the same time on the same dog (i.e.
with one being an incidental finding), only the one re-
sponsible for the clinical signs was retained. To facilitate
data processing, each case was assigned to one of the
following neuroanatomical categories, according to the
definitive diagnosis: encephalopathy, myelopathy, per-
ipheral nervous system (PNS) & muscles disorder, and
unclassified neurological condition. Diseases unrelated
to one of the above-listed categories, such as paroxysmal
dyskinesia, tremors syndromes and congenital deafness
were grouped together under unclassified neurological
Criteria used for the diagnosis of specific diseases
Definitive diagnoses for each patient were then estab-
lished by a board-certified neurologist based on patients
signalment and history, clinical findings and appropriate
ancillary tests, according to the current knowledge for
each condition. Ancillary tests comprised miscellaneous
blood testing (including biochemical analyses, serum bile
acids measurement, complete blood count, electrolytes,
hormonal testing, serology), cerebrospinal fluid (CSF)
analysis, PCR screening for various endemic infectious
agents of the nervous system, cytology and histology of
various tissues, otoscopy, bacterial culture on various
materials, muscles and nerves biopsies, myelography,
cross-sectional imaging (Computed tomography [CT]
and magnetic resonance imaging [MRI] scans), and elec-
trodiagnostics (electromyography, nerve conduction
studies and brainstem auditory evoked response
[BAER]). Two MRI devices were used during the study
period: a low-field (0.2 T) device prior to 2013, and a
high-field device (1.5 T) after 2013. Criteria allowing
diagnoses of diseases the most frequently expected are
listed in the following sections.
Brain diseases
When available, brain tumours were diagnosed based on
histological examination. In cases where a histological
examination was not performed, MRI criteria were used.
An intracranial glioma was defined as an intra-axial soli-
tary lesion, more or less enhancing after paramagnetic
intravenous contrast media administration, accompanied
or not by surrounding oedema and/or mass effect [11].
Similarly, pituitary neoplasia diagnosis was based upon
histological analysis and/or CT or MRI imaging features
(masses well-delineated in the pituitary area, more or
less invading the surrounding parenchyma with contrast
enhancement), along with consistent biochemical or
ultrasonographic abnormalities (hypercortisolism, bila-
teral adrenal enlargement etc. [12]). When the diagnosis
was achieved through imaging criteria, the term
Mayousse et al. BMC Veterinary Research (2017) 13:212 Page 2 of 10
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suspected neoplasiawas therefore used to refer to
these diseases.
In cases of absent histopathological diagnosis, meningo-
encephalitis of unknown (MUO) origin was diagnosed
based on the following previously described criteria: Focal
or multifocal clinical signs of brain disease, T2-weighted
multifocal intra-axial hyperintense lesions with variable
T1-weighted contrast enhancement on MRI, mononucle-
ated pleocytosis on CSF analysis, and exclusion of
endemic infectious diseases [13]. Idiopathic epilepsy
diagnosis was based upon the International Veterinary
Epilepsy Task Force consensus, and included normal
inter-ictal examination, normal brain MRI and CSF ana-
lysis, as well as a normal comprehensive biochemistry pro-
file investigating metabolic causes of seizures, including
serum bile acid and electrolytes [14]. Criteria allowing
diagnosis of otogenic bacterial encephalitis included
consistent central nervous system (CNS) clinical sings,
middle/inner ear MRI and/or CT abnormalities, T1-
weighted meningeal and/or brain parenchyma enhance-
ment on MRI, inflammatory CSF (with or without bacter-
ial culture), and a positive response to antibiotic
treatment. The diagnosis of metabolic encephalopathies
was based on clinical signs suggestive of brain disease,
consistent MRI findings and an identified metabolic origin
on blood analysis (e.g. hepatic or renal failure) [15].
Intervertebral disk herniation was diagnosed either by
CT, MRI or myelography associated with consistent
clinical signs and onset. The distinction between Hansen
type I and type II IVDH was based upon a combination
of clinical and imaging criteria and the perioperative ap-
pearance of herniated material in dogs that underwent
surgical treatment, as described in previous studies.
Hansen type I IVDH was suspected on CT if hyperdense
presumed disk material was observed in the interverte-
bral space and/or within the vertebral canal, along with
subsequent spinal cord compression on transverse
planes and/or epidural fat displacement [16]. It was sus-
pected on MRI if the disk had extruded through the an-
nulus fibrosus, and appeared as a compressive extradural
hypointense (either in T2 or T1-weighted) single lesion,
mostly lateralized and dispersed from either side of the
intervertebral space [17]. Hansen type I was suspected
during surgery if calcified/mineralized nucleus pulposus
was extruded in the vertebral canal and/or under the
dorsal longitudinal ligament [18].
Spinal arachnoid diverticulum (SAD) was defined on
myelography or CT-myelography as contrast-filled, tear-
drop shaped expansion of the subarachnoid space, with
a possible abrupt interruption of the contrast column
immediately after the lesion. On MRI, it was defined as
a T2-weighted hyperintense, T1-weighted and/or FLAIR
hypointense lesion of the subarachnoid space [19].
When histological examination was not performed,
usual previously described imaging criteria were used
to diagnose spinal tumours, especially regarding the
relationship between the lesion and the subarachnoid
space [20].
PNS & muscle disorders
Otitis interna was defined as the combination of clinical
signs suggestive of a peripheral vestibular syndrome,
evocative imaging findings either with CT (fluid-filled
tympanic bulla) or MRI (fluid-filled tympanic bulla and
loss of the normal T2-weighted hypersignal of the inner
ear), and evidence of inflammation/infection on bulla
cytology. Congenital deafness was defined as hearing loss
or deficits since birth, confirmed by a consistent BAER
study [21].
Data acquisition and statistical analysis
The clinical database of the institution was searched
using the clinical software (CLOVIS, 4Dv13) and appro-
priate keywords. When information was missing from
numerical records, the paper files were retrieved if avail-
able. For each case fulfilling the inclusion criteria, data
were recorded using a form created with EpiData v3.1
Software (Lauritsen J.M., Bruus M. & Myatt M., UK/
Denmark). Information regarding file number, age, sex,
body weight, duration of clinical signs, and definitive
diagnosis were collected. Complete data were then
exported into an Excel 2010 spreadsheet (Microsoft
Office 2010, Excel 2010) for further statistical evaluation.
Percentages for each subpopulation were calculated with
a 95% confidence interval, using the asymptotic/Wald
method (for groups in which n x p> 5, where n is the
number of individuals in the concerned subpopulation,
and p the estimate prevalence rate), or the exact bino-
mial/Clopper-Pearson method (for groups in which n x
p< 5, EpiTools, AusVet Animal Health Services). The χ
statistical test (or Fishers exact test when appropriate)
was used to assess the statistical association between age
(taken as a binary variable with appropriate cut-off ) or
sex, and the occurrence of IVDH or meningoencephalitis
of unknown origin. Odds Ratio (OR) were calculated to
quantify the association between sex and occurrence of
MUO, age and occurrence of IVDH, and were provided
with their 95% confidence interval (CI). A P-value < 0.05
was considered significant. Statistical tests were per-
formed using a website dedicated to statistical analysis
(BiostaTGV, A
receiver operating characteristic (ROC) curve analysis
was performed to determine a cut-off value for the age
that best discriminated the presence (versus absence) of
meningoencephalitis of unknown origin. The optimum
Mayousse et al. BMC Veterinary Research (2017) 13:212 Page 3 of 10
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cut-off value was determined with Youdens index
criteria. An appropriate statistical software was used for
the ROC analysis (SAS Software, version 9.3).
Study population
Between 2002 and 2016, 2846 FBs were presented at
our institution (representing 3.1% of all dog breeds),
all chief complaints and all departments combined.
Over this period of time, FB was the sixth most
popular breed after standard poodle (4.1% of all dogs
breeds), German shepherd (4.2%), Labrador retriever
(6.2%), Yorkshire terrier (6.8%) and mixed-breed dogs
(10.1%). A total of 533 FBs (18.7% of the 2846 FBs)
were presented for suspected neurological signs.
During the same period, a total of 88,863 dogs (FB ex-
cluded) were presented at our institution, of which 10,150
(11.4%) were admitted for neurological clinical signs.
Among the 533 FBs presented for neurological clin-
ical signs, 25 were excluded because the clinical
examination failed to identify a neurological disorder.
A further 165 animals were excluded because of in-
complete files and/or absence of definitive diagnosis.
In the end, 343 FBs with a confirmed neurological
disease and a precise diagnosis were included in the
statistical analysis, representing 12% of all FBs pre-
sented to the institution during the study period. The
whole case selection procedure is detailed in Fig. 1.
Two concomitant neurological conditions were diag-
nosed in only 9 dogs at the time of presentation.
Overall distribution of neurological diseases
In total, 64.7% of the 343 dogs presented a myelopathy
(n= 222 dogs, 95% CI 59.769.8%), 19.8% presented an
encephalopathy (n= 68, 95% CI 15.624.0%), 9.3% pre-
sented an unclassified condition (n= 32, 95% CI 6.5
12.9%) and 6.1% presented a PNS/muscle disorder
(n= 21, 95% CI 3.89.2%). The median age of the FBs in
this study was 4.0 years (range from 0.2 to 14.5 years).
There were 188 males (including 19 castrated dogs) and
155 females (including 64 spayed females). All the
results are detailed in Table 1.
Myelopathies distribution
Hansen type I intervertebral disk herniation was the
most common myelopathy, with 70.3% documented
cases (n= 156 dogs, 95% CI 64.376.3%). IVDH
accounted for 45.5% (95% CI 40.250.8%) of all the
neurological conditions, and for 5.5% of all FBs pre-
sented to our institution during the study period (95%
CI 4.66.3%). Five dogs presented two IVDH at the time
of presentation, representing a total of 161 sites of disk
herniation. Cervical IVDH accounted for 39.8% of all
IVDH (n= 64, 95% CI 32.247.3%), whereas thoracol-
umbar and lumbar locations represented 60.2% of IVDH
(n= 97, 95% CI 52.767.8%). There was no significant
association between sex and IVDH (p= 0.95). When
cervical and thoracic/lumbar IVDH were taken together,
most dogs (80.8%, 95% CI 74.687.0%) were more than
3 years old. Age was significantly associated with IVDH,
since 81% of FBs affected by IVDH were 3 years old or
533 eligible FB presented for
neurological clinical signs
508 FB presenting
actual neurological
clinical signs
343 FB with a
definitive diagnosis
165 FB excluded because
of incomplete file or lack
of definitive diagnosis
91 709 dogs presented to
the institution between
01/01/2002 and 01/01/2016
88 863 Non-FBs presented to
the institution during the
study period
10 150 Non-FBs presented
for neurological clinical
2 846 FB presented to the
institution during the study
25 FB excluded because
of clinical signs due to
Fig. 1 Data flow diagram illustrating the case selection procedure of the 343 French bulldogs (FB) selected from the general hospital population
between 2002 and 2016, and presenting neurological clinical signs and a definitive diagnosis
Mayousse et al. BMC Veterinary Research (2017) 13:212 Page 4 of 10
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more, compared to 64% of dogs affected by another
myelopathy (OR = 2.4, 95% CI 1.24.5, p< 0.01).
Spinal arachnoid diverticulum was the second most
common myelopathy, with 11.3% of dogs affected by this
condition (n=25,95%CI7.416.2%). SAD represented
7.3% of all diseases of the study (95% CI 4.510.0%). Com-
pressive vertebral malformation was diagnosed in 8.6% of
dogs with myelopathy (n=19,95%CI5.213.0%),
followed by a neoplastic condition (either spinal or verte-
bral neoplasia) in 3.2% of dogs (n= 7, 95% CI 1.36.4%),
syringomyelia in 2.7% of dogs (n= 6, 95% CI 1.05.8%),
and ischemic myelopathy in 1.8% of dogs (n=4,95%CI
0.054.5%). The remaining disorders of the spinal cord
were acute non-compressive nucleus pulposus extrusion
(n= 3), immune-mediated myelitis (n= 1), and lumbosa-
cral spinal cord dermoid sinus (n=1).
Cervical intervertebral disk herniation
The median age of dogs affected by cervical IVDH
was 4.2 years (range from 1.5 to 10 years), and the
median weight was 12.4 kg (range from 8 to 19 kg).
Cervical hyperesthesia, often pronounced, was
observed in 82.8% of dogs presenting cervical IVDH
(n= 53, 95% CI 73.592.0%). The most commonly af-
fected site in the cervical region was C3-C4 (57.8% of
cervical IVDH, n= 37, 95% CI 45.769.9%) followed
by C4-C5 (18.8%, n= 12, 95% CI 10.130.5%) and
C2-C3 (17.2%, n= 11, 95% CI 8.928.7%). An epi-
dural hematoma/haemorrhage was observed in 3 cases
that underwent cervical ventral slot surgery.
Thoracolumbar intervertebral disk herniation
Among these non-cervical IVDH (n= 97), 68 were lo-
cated in the thoracolumbar (T3-L3) region and 29 were
located in the lumbosacral (L4-S) region. The median
age of FBs affected by thoracic and lumbar IVDH was
4 years (range from 1.7 to 13 years). The median weight
was 12.4 (range from 4.5 to 18 kg). The most commonly
affected intervertebral spaces in this group of dog were
T13-L1 (20.6%, n= 20 95% CI 12.628.7%), followed by
L2-L3 (17.5%, n= 17, 95% CI 10.025.1%), L3-L4
(16.5%, n= 16, 95% CI 9.123.9%) and L1-L2 (14.5%,
n= 14, 95% CI 7.421.4%). Finally, T12-T13, L4-L5 and
other intervertebral locations regrouped 10 dogs each
(representing 10.3% of thoracolumbar IVDH each, 95%
CI 4.316.4%). An extradural haemorrhage and/or
hematoma was observed during cross-sectional imaging
and/or surgery in 27.8% (n= 27, 95% CI 18.936.8%) of
all cases diagnosed with thoracic or lumbar IVDH,
regardless of the affected disk location.
Spinal arachnoid diverticulum
Concerning SAD, 88.0% (n= 22, 95% CI 75.3100%)
were located in the thoracolumbar (T3-L3) region. More
Table 1 Distibution of the different neurological diseases in the
343 FBs from the study, with a definitive diagnosis
Category/Diseases N= 343 (%)
Myelopathies 222/343 (64.7%)
IVDH 156/222 (70.3%),
representing 161 IV sites
Cervical IVDH 64/161 (39.8%)
C3-C4 37/64 (57.8%)
C4-C5 12/64 (18.8%)
C2-C3 11/64 (17.2%)
C5-C6 4/64 (6.2%)
Non-cervical IVDH 97/161 (60.2%)
T13-L1 20/97 (20.6%)
L2-L3 17/97 (17.5%)
L3-L4 16/97 (16.5%)
L1-L2 14/97 (14.5%)
T12-T13 10/97 (10.3%)
L4-L5 10/97 (10.3%)
Other locations 10/97 (10.3%)
Spinal arachnoid diverticulum 25/222 (11.3%)
Thoracic 22/25 (88%)
Cervical 3/25 (12%)
Compressive vertebral malformations 19/222 (8.6%)
Hemivertebra + kyphosis 17/19 (89.5%)
Other CVM 2/19 (10.5%)
Spinal neoplasia 7/222 (3.1%)
Syringohydromyelia 6/222 (2.7%)
Other myelopathies 9/222 (4%)
Encephalopathies 68/343 (19.8%)
Brain neoplasia 25/68 (36.8%)
Glioma 17/25 (68%)
Pituitary neoplasia 5/25 (20%)
Other neoplasias 3/25 (12%)
MUO/optic neuritis 17/68 (25%)
Idiopathic epilepsy 9/68 (13.2%)
Infectious encephalitis 8/68 (11.8%)
Metabolic 3/68 (4.4%)
Other encephalopathies 6/68 (8.8%)
Unclassified neurological conditions 32/343 (9.3%)
Congenital deafness 29/32 (90.6%)
Bilateral 21/29 (72.4%)
Unilateral 8/29 (27.6%)
Other unclassified conditions 3/32 (9.4%)
PNS/muscle disorders 21/343 (6.1%)
Otitis interna/PVS 14/21 (66.7%)
Myopathies 3/21 (14.3%)
Idiopathic vestibular syndrome 2/21 (9.5%)
Others PNS/muscle disorders 2/21 (9.5%)
FB French bulldog, IVDH intervertebral disk herniation, IV intervertebral, CVM
compressive vertebral malformation, MUO meningoencephalitis of unknown
origin, PNS peripheral nervous system, PVS peripheral vestibular syndrome
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than three quarters of the thoracolumbar SAD cases
were located between T9 and T12 (77.3%, n= 17, 95%
CI 59.894.8%). In the remaining 12.0% (n=3,95%CI
0.024.7%) of animals affected by this condition, a
cervical (C1-C5) location of the SAD was observed. No
SAD was found in the caudal cervical (C6-T2) or lumbo-
sacral (L4-S) segments. In addition, a vertebral malfor-
mation (n= 12) or a mild IVDH (n= 4), at the level or
distant from maximum 2 to 3 vertebral bodies to the
SAD, was identified in 64.0% (n= 16, 95% CI 45.2
82.8%) of all cases. The median age of FBs affected by
SAD was 4.5 years (range from 1 to 10.7 years).
Compressive vertebral malformations
Concerning the 19 dogs clinically affected by congenital
vertebral malformations, 17 presented with hemiverteb-
rae (89.5%, 95% CI 75.7100%) associated with a major
kyphosis responsible for a compression of the spinal
cord. The most commonly affected vertebrae were T6,
T7, T8, and T10 (with 3 abnormal vertebrae for each).
Five FB presented with two or more malformations. One
dog presented with a wedge-shaped vertebrae and one
dog presented with L6-L7 spina bifida.
Encephalopathies distribution
Brain neoplasia
A suspected brain neoplasia was observed in 36.8% of
FBs affected by an encephalopathy (n= 25, 95% CI
28.653.3%), with a glioma, either suspected or con-
firmed, being the most common (n= 17, 68% of all
neoplasias 95% CI 49.786.3%). Five FBs presented a
pituitary macroadenoma (n= 5, 20.0% of neoplasias
95% CI 6.840.7%). The three remaining animals were
affected by intracranial lymphoma, malignant intracra-
nial peripheral nerve sheath tumour of cranial nerve
III, or suspected osteosarcoma of the calvarium.
Three gliomas and 2 pituitary macroadenomas were
confirmed histologically (either with biopsies or post
mortem examinations). The median age of FBs with
brain neoplasia was 9.0 years old (range from 5 to
14.5 years).
Meningoencephalitis of unknown origin
Meningoencephalitis of unknown origin represented
25.0% of the encephalopathies (n= 17, 95% CI 15.3
37.0%). The median age of FBs affected by MUO was
2.25 years (range from 0.8 to 6.5 years). Among the 68
(19.8%) FBs that presented an encephalopathy, MUO
was more frequently observed in females than in males
(OR = 7.1, 95% CI 2.025.2, p< 0.01). ROC curve ana-
lysis enabled us to determine that the cut-off age that
best discriminated the presence versus the absence of
MUO was 5.5 years, with a sensitivity of 60.7% and a
specificity of 94.1% (Area under the curve = 0.76).
Therefore, by using this cut-off, 94.1% of FBs less than
5.5 years old presented with clinical signs related to an
encephalopathy were affected by MUO, whereas 60.7%
of FBs of 5.5 years old or more presented with the same
clinical signs were not affected by this condition.
Other encephalopathies
Regarding other conditions, idiopathic epilepsy repre-
sented 13.2% of encephalopathies (n= 9, 95% CI 6.2
23.6%), and bacterial encephalitis associated with otitis
media/interna 11.8% (n= 8, 95% CI 5.221.9%). The
remaining encephalopathies were metabolic encephalop-
athies (n= 3, two hepatic encephalopathies, and one
uraemic encephalopathy), congenital hydrocephalus
(n= 2), cannabinoid intoxications (n= 2), ischemic
stroke and degenerative encephalopathy (n= 1 for each
Other neurological conditions distribution
Among the unclassified neurological disorders (n= 32),
90.6% of FBs presented congenital deafness (n= 29, 95%
CI 80.5100.0%). Bilateral deafness was detected in
72.4% (n= 21, 95% CI 56.188.7%) of animals presenting
congenital deafness, versus 27.6% for the unilateral form
of the condition. Among all FBs presented with congeni-
tal deafness, 79.3% were white or had white in their coat
(n= 23, 95% CI 64.694.1%). Idiopathic head tremors
were observed in 2 animals, and narcolepsy/cataplexy in
a single case.
Among PNS/muscles disorders (n= 21), 66.7% of
animals presented an otitis interna with neurological
signs (see below, n= 14, 95% CI 46.586.8%), 14.3%
presented a myopathy (n= 3, 95% CI 3.036.3%),
immune-mediated polymyositis, ischaemic neuromyo-
pathy and corticosteroids-induced myopathy. Two
animals presented an idiopathic acute vestibular
syndrome, one case presented a chronic steroid-
responsive polyneuropathy, and one case presented a
malignant peripheral nerve sheath tumour. Among
the FBs affected by otitis media/interna, all animals
were presented with a peripheral vestibular syndrome,
eight cases had concurrent ipsilateral facial paralysis,
and four cases had a concurrent Horner syndrome.
This study revealed that 18.7% of FBs admitted in our
institution during the study period presented with
neurological clinical signs, 12% when only dogs with
definitive diagnosis are considered. Although the
hospital population of FBs in this study roughly re-
flects the general FB population (mostly in good
health), this percentage is probably overestimated as a
large majority of dog are presented to our institution
Mayousse et al. BMC Veterinary Research (2017) 13:212 Page 6 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
for health issues. However, the objective of the
current study was not to estimate the prevalence rate
of neurological disorders in the general FB popula-
tion, but rather among FBs presented to a veterinary
This study showed that the FB breed is affected by
various neurological conditions, even if disorders of the
central nervous system (CNS) were clearly predominant
in this population. Hansen type I IVDH was by far the
most prevalent neurological disease of FBs in this study,
as it represented nearly half the overall conditions of the
whole nervous system (45.5%), and 5.5% of all FBs pre-
sented to our institution during the study period. In a
large American study evaluating inherited disorders in
pure-breed and mixed-breed dogs, FB was found to be
the second breed most frequently affected by IVDH after
the Dachshund [8].
An important finding is that nearly 40% of IVDH in
FBs from this study occurred in the cervical area. In
other breeds, several studies demonstrated a lower
percentage of cervical IVDH in comparison to
thoracic-lumbar IVDH, rather located around 20
25%, especially in Dachshund [2224].However,an
almost similar cervical versus thoracic-lumbar IVDH
repartition has been reported in Beagle or Cocker
Spaniel in a older study, even if the number of dogs
in these breeds was limited [24].
Regarding IVDH position, the C3-C4 intervertebral
space was the most frequently involved site, all locations
combined. This contrasts either with recent [25] or older
[26] findings indicating that C2-C3 was the most
commonly affected disk in chondrodystrophic dogs pre-
senting cervical IVDH, although only a small number of
FBs were mentioned in the most recent report (n= 5).
In the thoracolumbar area, T13-L1 was the most fre-
quently affected site, followed by L2-L3 and L1-L2 in FB
of our study. This is in partial agreement with previous
publications revealing that the most often affected site in
canine thoracolumbar IVDH was T12-T13, followed by
T13-L1 and T11-T12 intervertebral spaces [2729].
Note that the majority of dogs which constituted the
populations in these previous studies were Miniature
Dachshunds and not FBs. Conversely, IVDH were dis-
tributed more equitably between T13 and L4 in the FB
reported here, which is consistent with a previous publi-
cation demonstrating that FB present thoracolumbar
IVDH more caudally than Dachshund [28].
The median age of the FBs affected by cervical and
thoracic-lumbar IVDH in the present study was 4.2
and 4.0 years respectively, which tends to be younger
than in other breeds for both locations. Regarding
Hansen type I thoracic-lumbar IVDH, this is indeed
in contrast with the largest case series in which the
estimated mean and median age is around 6 years
old, all breeds combined [2730]. Nonetheless, a sin-
gle study comparing thoracolumbar Hansen type I
IVDH in FB and Dachshunds showed that FBs were
younger at the time of surgery [28], even if the num-
ber of FBs was limited in this report (n= 47). Simi-
larly, studies addressing cervical IVDH revealed a
median age ranging between 6 and 8 years old in
chondrodystrophic dogs [25, 26, 31]. One hypothesis
for this difference could be the fact that intervertebral
disk degeneration occurs faster in FB than in other
chondrodystrophic breeds. However, no study has yet
compared the disk degeneration kinetic between
chondrodystrophic breeds. Another recent study dem-
onstrated that congenital vertebral malformations,
common in FB, could promote intervertebral disk
degeneration in the adjacent intervertebral spaces in
chondrodystrophic breeds [32].
SAD was the second most frequent myelopathy and
was identified in 25 dogs from this study, constituting
the largest published population of FBs diagnosed with
this condition. SAD was preponderant in the middle to
caudal thoracic area in the FBs of this study. These
findings regarding SAD location are consistent with a
previous publication [7], the thoracic region being the
most frequently affected in small chondrodystrophic
breeds, such as Pug or FB. In addition, a potential
underlying cause such as vertebral malformation or mild
IVDH was identified in 64.0% of the cases of SAD in this
study. This observation is also in agreement with the
publication by Mauler and colleagues [7], which revealed
that 61.5% of the 13 FBs reported in this study presented
a concurrent spinal disorder. This could therefore pre-
dispose FB for acquired SAD in the thoracic area of the
spinal cord. Compressive thoracic vertebral malforma-
tions resulting in a myelopathy were found in nearly 9%
of FBs in this report, mainly represented by mid to cau-
dal thoracic hemivertebrae. The true prevalence of verte-
bral malformation is however higher in FB, as
asymptomatic dogs may present this abnormality [33],
while only symptomatic FBs were included in the
present study. A recent study showed indeed that verte-
bral malformations in neurologically normal FBs were
detected in 93.5% of cases, and were more frequently
observed than in other chondrodystrophic brachy-
cephalic dog [34].
Encephalopathies were the second most frequently
observed condition of the nervous system in this FBs
population. Brain neoplasia appeared to be the
primary cause of encephalopathy within this subpopu-
lation, with glial tumour (either suspected or histolog-
ically confirmed) being the most frequent. This
finding is in agreement with a past study, which re-
vealed that FB, among other brachycephalic dogs,
seems predisposed to gliomas [9]. Nevertheless, the
Mayousse et al. BMC Veterinary Research (2017) 13:212 Page 7 of 10
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diagnosis of glioma was not definitive in all cases in
our study, as necropsy or biopsies were not per-
formed in all animals presented with a brain tumour.
In these cases, the diagnosis was based mainly on
MRI characteristics. Even if several studies provided
interesting MRI features giving indications for the dif-
ferentiation in the tumour nature or subtype, these
parameters remain to be improved, as they lack sensi-
tivity and specificity [3537]. The second most fre-
quent encephalopathy was meningoencephalitis of
unknown origin, which was found to be more com-
mon in small young to middle-aged female dogs ac-
cording to a meta-analysis from 2010 [13]. In the
present study too, FBs less than five and a half years
old seemed more likely to be affected by MUO than
other causes of encephalopathies, although the sensi-
tivity for the selected cut-off value was not optimal.
Similarly, females in the present population of FBs
appeared to be more likely affected by this condition
than male dogs, which is consistent with previous
data [13].
Congenital deafness was the more frequently detected
unclassified neurological disease, as 90.6% of FBs in this
subpopulation were affected by this condition. Congeni-
tal deafness has been described in many canine breeds,
including FB [38], and has been associated with the pres-
ence of white colour in coat or blue eyes in various
breeds [38, 39]. Deaf FBs from our study were either
white or contained white in their coat in nearly 80% of
cases. The prevalence of bilateral deafness is usually
lower than unilateral deafness according to several con-
cordant studies [3942]. Surprisingly, bilateral deafness
was diagnosed more frequently than unilateral deafness
in the FBs of this study, as 72.4% of the dogs were
bilaterally deaf. This observation needs to be validated
by other referral centres as several individuals were
presented for auditory function screening purpose.
Otitis media/interna associated with peripheral ves-
tibular syndrome was the most common disease in
dogs presented with PNS/muscles disorders. This is
in agreement with a previous study suggesting that
the primary cause of peripheral vestibular syndrome
in dog was otitis media/interna [43]. However, there
was no information regarding the predisposition of a
specific breed. To the authorsknowledge, no infor-
mation is available in the veterinary literature regard-
ing the potential predisposition of a particular canine
breed for otitis interna/vestibular neuritis. This
disease might eventually spread to the overlying brain
and/or meninges in some cases, thus resulting in
bacterial meningoencephalitis [44].
The study period was specifically chosen after 2002
in order to minimize the measurement bias regarding
conditions that required an MRI scan for accurate
diagnoses. This date corresponds in fact to the arrival
of a MRI device in our institution. However, a meas-
urement bias may still exist because MRI scans were
performed on a low-field device prior to 2013,
whereas a high-field device was used after 2013. This
may have affected the detection of certain disorders,
such as MUO, immune-mediated myelitis or idio-
pathic epilepsy, even if a study in people revealed
only subtle differences in the detection of brain le-
sions between low-field and high-field MRI devices
[45]. Indeed, mild brain anomalies may be missed
with a low-field MRI device, and a dog wrongly
classified has having idiopathic epilepsy for example.
Finally, the FBs population in this study may differ
from that encountered in other referral centres, as
the number of insured dogs is probably higher in UK
and North America than in France. This may have
have decreased the number of detailed clinical cases
with a definitive diagnosis, and thus the prevalence
rates of certain diseases.
This is the first study addressing neurological condi-
tions as a whole in a large cohort of FBs, and this
further confirms the general impression of many vet-
erinarians regarding the overall distribution of these
disorders. Hansen type I IVDH appeared to be by
far the most frequent neurological disease in middle-
aged FBs, representing 5.5% of all FBs presented
during the study period. FB tends to be more fre-
quently affected by cervical IVDH than other breeds,
and at a younger age. The topographical distribution
indicates a greater tendency for involvement of the
C3-C4 intervertebral disk.
SAD was the second most commonly diagnosed
myelopathy, with an associated spinal abnormality in
nearly two thirds of the cases. Suspected brain
tumours and MUO were the most frequent encephal-
opathies, the latter preferentially affecting young to
middle-aged female patients. Otitis interna with per-
ipheral vestibular signs and bilateral congenital deaf-
ness associated with white coat, were also frequently
observed, apart from CNS conditions. The high
prevalence of various neurological diseases identified
in this study might be explained by the specific body
conformation of FB. This hypothesis needs however
to be verified through comparative studies with other
breeds, further multicentric studies in European and
North American referral centres, and largest represen-
tative populations. Findings of the present study could
be of interest for FBs owners and breeders, practicing
veterinarians and pets insurance companies.
Mayousse et al. BMC Veterinary Research (2017) 13:212 Page 8 of 10
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
BAER: Brainstem auditory evoked response; CNS: Central nervous system;
CSF: Cerebrospinal fluid; CT: Computed tomography; FB: French Bulldog;
FLAIR: Fluid attenuated inversion recovery; IVDH: Intervertebral disk
herniation; MRI: Magnetic resonance imaging; MUO: Meningoencephalitis of
unknown origin; PNS: Peripheral nervous system; SAD: Spinal arachnoid
The authors want to thank TVM Laboratories.
The Neurology Unit is partially supported by TVM Laboratories. However,
TVM Laboratories did not directly fund this study.
Availability of data and materials
The datasets used and/or analysed during the current study are available
from the corresponding author on reasonable request.
VM, AJ and SB conceived the study. VM collected all data and write the
manuscript. LD designed and participated in the statistical analysis. AJ and
SB participated in the revision of the manuscript. All authors read and
approved the final manuscript.
Ethics approval and consent to participate
The retrospective analysis is exempt from ethics approval from the
institutional animal care and use committee.
Consent for publication
Not applicable.
Competing interests
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.
Author details
Université Paris-Est, Ecole Nationale Vétérinaire dAlfort (EnvA), Unité de
Neurologie, 7 avenue du général de Gaulle, 94700 Maisons-Alfort, France.
Université Paris-Est, Ecole Nationale Vétérinaire dAlfort (EnvA), Unité de
Biostatistiques et dEpidémiologie Clinique, 7 avenue du général de Gaulle,
94700 Maisons-Alfort, France.
Inserm, IMRB U955-E10, 8 rue du général
Sarrail, 94000 Créteil, France.
Present adress: Davies Veterinary Specialists,
Manor Farm Buisiness Park, Higham Gobion, Herts SG5 3HR, United Kingdom.
UMR BNMS Neurobiologie, Ecole Nationale Veterinaire dAlfort, 7 avenue du
General de Gaulle, 94700, Maisons Alfort, France.
Received: 26 January 2017 Accepted: 26 June 2017
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... The French Bulldog (FB), a brachycephalic and chondrodystrophic breed, has a high prevalence of neurological diseases, such as intervertebral disc disease (IVDD), vertebral malformations (that may induce canal stenosis and kyphosis), and spinal arachnoid diverticulum [14,15], which may be associated with SHM. In this breed, Ricco et al. [16] reported a prevalence of 67% for CM, 42% for spinal dorsal compression at C1-C2, 42% for cervical disc herniation, and 8% for SHM. ...
... The samples included in each control panel were different (Table S1): control panel 1 (CP1) included WGS data from 16 dogs belonging to nine established breeds (3 Sloughi, 2 Dalmatian, 1 German Wirehaired Pointer, 2 Gordon Setter, 1 Great Pyrenees, 1 Komondor, 2 Shiba Inu, 3 Siberian Husky, 1 Weimaraner); and control panel 2 (CP2), 16 individuals from five different breeds (3 Bouvier des Flandres, 3 English Setter, 4 Great Dane, 4 Rottweiler, 2 Saint Bernard). The 10 FBs controls were 5 years of age or older (based on mean ages from other neurological studies in FBs; [14]), with MRI of the complete spine showing the absence of SHM regardless of the presence of other spinal diseases ( Table 1). The 32 additional control samples were extracted from the VCF file with NCBI accession number PRJNA448733 [18] and no MRI data is available for them. ...
... Finally, a single base deletion in the DVL2 gene has been related to twisted and truncated tail (screw tail), vertebral malformations and brachycephalic phenotype in Bulldogs, FBs and Boston terriers [34,35] . The vast majority of the FBs included in our study, both cases and controls, have other concomitant neurological and morphological problems, the most frequent being IVDD and vertebral malformations, which is in accordance with a high prevalence of these alterations in this breed [14]. Despite the fact that they occur in both groups of dogs, it is known that these traits may collaborate in the development of SHM, but are seldom the direct cause of this condition, as proved by the presence of SHM without other concomitant neurological diseases and vice versa. ...
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Syringohydromyelia (SHM) is a neurological disorder characterized by the appearance of fluid-containing cavities within the spinal cord. Although SHM is thought to be under multigenic control, the molecular basis of this disease remains poorly defined. A genome-wide association study (GWAS) was carried out comparing the whole genome sequences (WGS) from 12 dogs with SHM and 2 panels of 26 dogs (either older than 5 years and showing the absence of SHM or belonging to breeds not susceptible to SHM) to identify candidate genes associated with the development of SHM. Seven candidate genes were identified. Of these, five genes were determined to be involved in bone development (PLXNA2, HHAT, MBOAT2, ITGAV) and calcium homeostasis (HPCAL1). Although further validation is needed at the transcript level, it is worth highlighting the association of a possible pathogenic variant which generated a new intronic branch-site sequence in PLXNA2 (T/C, CFA7:7043294). Considering previous studies in dogs that show SHM related to craniocervical junction (CCJ) malformations, these genes can be considered good candidates for the development of this disease. This report dissects the genomic component of SHM in dogs, which paves the way for further research on this complex disease found both in canine and human species.
... Over the last few decades, French bulldogs (FBs) have gained increased popularity (2). Unfortunately, this breed is more frequently affected by cervical intervertebral disk herniation (IVDH) than other dog breeds (3,4). FBs suffer from intervertebral disk (IVD) degeneration at an early age (4,5), thereby inducing IVDH occurring at a median of 4.2 years (3). ...
... It is known that FBs are more likely to suffer from cervical IVDH at the level of C3-C4 (3) unlike other chondrodystrophic breeds that are more commonly affected at C2-C3 (6,7). However, the causative background of this phenomenon remains partially understood (3,8). ...
... Particularly in the cranial part of the cervical spine, and especially at the level of C3/C4, FBs had a significantly steeper angulation compared to dachshunds and Labrador retrievers (1). This supports the hypothesis that steeper IVD confirmation might be another additional biomechanical risk factor for developing IVDH due to a significantly different compressive loadbearing and force transmission (3). It was conceivable that synergizing both findings, less steep angulation and a lesser amount of paraspinal dorsal musculature, might provide a further biomechanical possible explanation for cervical IVDH occurring preferentially at C3/C4 in FBs. ...
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Objective: To objectively assess the cervical paraspinal musculature of French bulldogs (FBs) using computed tomography (CT) scan-based measurements, outline differences in other breeds published in the literature, and investigate the potential influence of its cervical paraspinal musculature on predisposed sites for intervertebral disk disease. Animals: Thirty FBs that underwent CT scans of the cervical spine from the skull to C7/T1 were enrolled. Fifteen dogs were patients suffering from intervertebral disk herniation (IVDH group), and 15 dogs underwent CT scans due to brachycephalic obstructive airway syndrome (BOAS group). Methods: At the level of each cervical intervertebral disk from C2/C3 to C7/T1, measurements were performed and statistically analyzed. On the sagittal CT scan reconstruction, the height ratio of the dorsal to ventral paraspinal musculature and the angle of the disk axis to vertebral body length were assessed. On the transverse plane, the area ratio of the dorsal and ventral paraspinal musculature and the ratio of force moments were determined at each intervertebral disk level. Finally, ratios were compared to the values of Labrador retrievers and dachshunds published by Hartmann et al. ( 1 ). Results: Comparing the two FB groups, one significant difference was detected in the mean height ratio of the dorsal to ventral paraspinal musculature at the level of C5/C6 ( P = 0.0092) and C6/C7 ( P = 0.0076), with IVDH FBs having the more prominent dorsal paraspinal musculature. At the level of C3/C4, a significantly less prominent dorsal paraspinal musculature in FBs than in dachshunds ( P = 0.0058) and a significantly steeper disk to vertebral body angulation were observed ( P = 0.0005). Conclusion: Although some incidental differences were found, most parameters did not significantly differ between the BOAS and IVDH FBs. Significant conformational differences in the cervical paraspinal musculature and disk to vertebral body length angulation were found between FBs and two other breeds (chondrodystrophic and non-chondrodystrophic). This study's findings suggest that the paraspinal musculature is an additional biomechanical influencing factor on the preferential sites of IVDH in the cervical spine and that other major factors exist in IVDH development, especially in FBs.
... In the present study, the median age at onset of neurological deficits was 9.58 years. Median age reported recently elsewhere ranged from 6.8 years to 12.68 years [2,31,[37][38][39]. This apparently wide range in age could represent the different study inclusion criteria. ...
... Idiopathic vestibular syndrome tends to appear more frequently in older dogs in contrast to meningoencephalitis of unknown origin, which is a frequent cause of central vestibular syndrome. It mainly affects female brachycephalic dog breeds younger than 5.5 years [39]. Neurological examination is a very accurate clinical tool to determine the presumed neuroanatomical localisation of neurological diseases within the vestibular system in more than 90% of cases, according to Bongartz et al. (2020) [35]. ...
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Background Vestibular syndrome is often accompanied by nausea. Drugs currently approved for its treatment have been developed to stop vomiting but not nausea. The efficacy of 5-HT 3 receptor antagonists to reduce nausea has been described for chemotherapy, but not for nausea secondary to vestibular disorders. Methods Sixteen dogs with vestibular syndrome-associated nausea were included in the open-label, multicentre study. The intensity of nausea-like behaviour was analysed before ondansetron administration (0.5 mg/kg i.v.) and 2 h afterwards, using a validated 5-point-scale. The occurrence and frequency of salivation, lip licking, restlessness, vocalisation, lethargy, and vomiting were assessed. Results All dogs initially showed signs of nausea, whereas only 31% showed vomitus. The intensity of nausea was significantly reduced in all dogs ( p ≤ 0.0001) 2 h after ondansetron administration, including the clinical signs of nausea analysed in 11 dogs (salivation [ p = 0.0078], lip licking [ p = 0.0078], restlessness [ p = 0.0039], and lethargy [ p = 0.0078]) except for vocalisation ( p > 0.9999). Conclusions The results provide preliminary evidence of the potential benefit of ondansetron in the treatment of nausea, which was present in all examined dogs. Vomiting was only observed in 5 dogs indicating that nausea can occur separately and should not be perceived only as a preceding stimulation of the vomiting centre.
... French Bulldogs became a popular breed in Europe and the United States. Mayousse et al. reported a high prevalence of extradural hemorrhage or hematoma (27.8% of all cases diagnosed with intervertebral disc extrusion) in a large study on the prevalence of neurological diseases in French Bulldogs [18]. ...
Intervertebral disc extrusion associated with extensive epidural hemorrhage (DEEH) is a well-documented pathological condition in veterinary medicine. This retrospective study aimed to evaluate the prevalence and clinical features of DEEH in a population of French Bulldogs affected by intervertebral disc extrusion (n=75), compare the findings with those from a group of Dachshunds (n=98) and identify possible predictive factors of DEEH and outcomes in surgically treated patients. The study showed that the prevalence of DEEH observed in Dachshunds (11.2% [95% confidence interval [CI]: 5.7-19.2%]) was significantly lower than that observed in French Bulldogs (41.3% [95% CI: 30.1-53.3%]). The multiple logistic regression model highlighted that the patients presenting with an acute onset of clinical signs (>24 hr) (odds ratio [OR]: 13.08; 95% CI: 4.63-37.03, P=0.00), presence of clinical signs progression (OR: 5.04; P=0.01), and French Bulldogs (OR: 5.15; 95% CI: 1.71-15.54, P=0.00) were at increased risk of developing DEEH. Secondary analysis showed that patients with DEEH were at an increased risk of being non-ambulatory at discharge (OR: 3.43; P=0.017). Overall, the surgically treated patients had favorable outcomes.
... However, as the present study is a single centre observational study, with a quantitatively limited and specific patient population, it may differ from that encountered in other referral centres, therefore, the current conclusions cannot necessarily be translated to other canine populations, or different clinical conditions. Some breeds such as the French Bulldog and English Bulldog (8 cases in total) are over represented compared to others, and although this data is in accordance with the higher prevalence of intervertebral disc disease reported in these breeds (Bellumori et al. 2013;Mayousse et al. 2017), they also present other peculiarities such as significantly lower PaO2, and higher tHb compared to meso and dolichocephalic dog breeds (Hoareau et al 2012). The higher Hb, which might be a possible compensatory mechanism to maintain normal arterial content of oxygen in brachycephalic dogs, may have had some direct influence on the results presented in our study (e.g. ...
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Total haemoglobin concentration tHb, arterial haemoglobin saturation (SaO2), and arterial oxygen content (CaO2) are indicative of a patient’s ability to transport oxygen (O2) and can be used to guide clinical decisions. Laboratory-based methodologies such as the haematology analyser, laboratory CO-Oximetry, and point-of-care analysers have been used to assess these values, but despite being accurate all these instruments require a blood sample, allow only intermitted monitoring, are operator-dependent, and introduce a delay in obtaining results. Pulse CO-oximetry, by combining the principles of CO-Oximetry with pulse oximetry enables noninvasive measurements of the Hb (SpHb) and derived values. Whilst the Masimo pulse COoximeter has given the approval by the Food and Drug Administration (FDA) and European Medical Agency (EMA), there is still debate within the scientific literature regarding its accuracy. In a recent version of the pulse CO-oximeter software, a so-called in-vivo adjustment that allows initial calibration of the SpHb against a measured laboratory value has been introduced with the intent to increase accuracy (Miyashita et al. 2014; Frasca et al. 2015; De Rosa 2020).To date, in veterinary medicine only three studies have investigated the performances of pulse CO-oximetry, but none of them have investigated the accuracy of SpHb after in-vivo adjustment. With the hypotheses that in-vivo adjustment would increase the accuracy of subsequent SpHb measurements, the aim of this thesis was to assess the agreement of pulse CO-oximeter derived values of tHb [H], CaO2 and SaO2, using an optical fluorescencebased blood gas analyser and oximeter (VetStat®) as the reference method. This thesis hypothesises that the accuracy of SpHb and SpO2 will be influenced by perfusion index (PI), mean arterial pressure (MAP) and tongue thickness. Furthermore, clinical significance and trending accuracy were tested with error grid and four quadrant plot analysis. A total of 39 data pairs of tHb were obtained before in-vivo adjustment in as many dogs. The mean [Hb]-SpHb difference was -2.7 g dL−1 with limit of acceptance (LoA) of -4.9 to -0.5 g dL−1. After in-vivo adjustment from the same dogs, 104 data pairs were obtained; the mean [Hb]-SpHb difference, after in-vivo adjustment, was -0.2 g dL−1 with LoA of -1.1 to 0.6g dL−1. The mean SaO2-SpO2 difference was 0.86% with LoA of -0.8 to 2.5% and between CaO2 -SpOC was 0.66 ml dL-1with LoA of -2.59 to 3.91 ml dL-1. Zone A of the error grid encompassed approximately 98% of data pairs for SpHb. The concordance rate for consecutive changes in SpHb and [Hb] performed with four quadrant plot analysis was 92.6%. Before in-vivo adjustment, pulse CO-oximetry derived values overestimated the spectrophotometric-based blood gas analyser [Hb] and CaO2 values. Following in-vivo adjustment, the accuracy, precision, and LoA markedly improved. The accuracy of SpHb and SpO2 were not influenced by PI, MAP and tongue thickness and pulse CO-oximetry, after in-vivo adjustment, adequately tracked the changes of Hb within the time confirming a good trending accuracy. Furthermore, the Masimo’s performance was evaluated in dogs referred to the University of Glasgow Small Animal Hospital for a variety of emergency surgeries and presented in hypovolemic states, and/or acute haemorrhagic states. The findings from our observational study shown an acceptable [Hb]-SpHb difference, and a consistent fall in SpHb values during bleeding episodes. This finding may support the use of pulse CO-oximetry devices as an intraoperative starting point for deciding when to perform an invasive tHb measurement. Nevertheless, in all patients receiving synthetic colloids and/or vasoactive drugs (noradrenaline infusion) the increase in [Hb]-SpHb difference suggests that values displayed by the Masimo Radical-7 under these circumstances should be considered carefully and always confirmed by an invasive blood sample. In conclusion, pulse co-oximetry and SpHb monitoring, after in-vivo adjustment, cannot completely replace invasive measurements, but show definite promise for use during surgical procedures
... The most common breeds in this study suffering from IVDH were french bulldog (n = 12; 19.4%) and dachshund (n = 12; 19.4%) to equal parts. These results are in concordance to findings of previous studies [1,13,34]. ...
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Intervertebral disc herniation (IVDH) is a frequently occurring neurological disease of dogs and the most common reason for spinal cord injury (SCI). Clinical signs are variable thus a reliable prognosis is crucial for further treatment decisions. Currently, the prognosis of IVDH primarily depends on presence or absence of deep pain perception. The purpose of this study was to investigate if Th17-cells could serve as a potential, prognostic biomarker for IVDH. We investigated a possible role of the adaptive immune system in the pathophysiology of IVDH in dogs. The investigation was performed by analyzing the influence of Th17-cells in blood and cerebrospinal fluid (CSF) of sixty-two dogs suffering from IVDH. In addition, we examined if Th17-cells might influence the course of this disease. As controls, paired blood and CSF samples of ten healthy clinic-owned dogs were examined and the values were compared to those of the IVDH group. Isolated lymphocytes were analyzed after stimulation by using multicolour flow cytometry to measure the number of Th17-cells. IL-17 levels were measured in paired serum and CSF samples by Enzyme‐linked Immunosorbent Assays (ELISA). Highly significant differences of stimulated Th17-cells in EDTA-blood samples could be determined between Th17-cell levels of dogs suffering from IVDH and the healthy control group and also between three sampling time points: preoperative, after clinical improvement and after six months. Preoperatively, Th17-cell levels were strongly decreased in contrast to the healthy controls. The decreased amount of Th17-cell levels recovered postoperatively so that Th17-cell levels of the last follow-up examinations were comparable to the control group after six months. At the same time IL-17 measured in serum preoperatively was significantly higher in dogs with IVDH than in healthy controls. However, there was no considerable difference of IL-17 measured in CSF between the groups. In conclusion, a high activity and consequent consumption of IL-17-producing Th17-cells is suspected in acute IVDH. These findings may indicate an involvement of Th17-cells in the pathogenesis of IVDH and emphasize that these cells might be involved in the interaction of pain, stress and immune reaction. However, based on the findings of this study the development of Th17-cells as a biomarker cannot be recommended, yet.
OBJECTIVE To compare spinal cord-to-vertebral canal area ratios measured with CT between the cervical and thoracolumbar regions in French Bulldogs. ANIMALS 37 French Bulldogs presented to a referral hospital between 2016 and 2019. PROCEDURES The study was conducted as a retrospective observational study. Exclusion criteria were evidence of vertebral malformations or spinal cord compression at the sites where measurements were obtained and the presence of cervicothoracic or thoracolumbar transitional vertebrae or neurologic deficits. CT images were reviewed, and measurements were performed by 2 investigators. Measurements of the spinal cord and vertebral canal were made at the level of or immediately cranial to the midbodies of C5 and L1. RESULTS A 2-tailed, paired t test indicated that the mean spinal cord-to-vertebral canal area ratio differed significantly ( P < .01) between C5 (0.726) and L1 (0.605). The ratio was lower in the thoracolumbar region, suggesting that the vertebral canal was relatively larger in this region. CLINICAL RELEVANCE The epidural space did not appear to be larger in the cervical than in the thoracolumbar region in this population of French Bulldogs, contrary to previous reports. The reason for the more severe deficits observed with thoracolumbar disk extrusion in this breed remains to be characterized.
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Background: Intervertebral disc-associated epidural hemorrhage (EH) in dogs is a poorly understood neurological condition. Objective: To compare the clinical presentation, magnetic resonance imaging (MRI) changes, and clinical outcome of dogs with acute thoracolumbar intervertebral disc herniation (TL-IVDH) with and without EH. Animals: One hundred sixty client-owned dogs that underwent MRI and hemilaminectomy for acute TL-IVDH at a private practice in Colorado, including 63 dogs with EH and 97 dogs without EH. Methods: Retrospective review of medical record data from 160 dogs presenting sequentially to a single practice with acute TL-IVDH that underwent MRI and hemilaminectomy surgery. Results: Sixty-three of 160 (39%) dogs had confirmed EH. French Bulldogs were significantly overrepresented (23/63; odds ratio [OR]: 4.1; 95% confidence interval [CI]: 1.8-9.0; P < .001) of the EH cases. Dogs with EH were more likely to present with clinical signs less than 48 hours than were dogs without EH (24-48 vs 48-72 hours; OR: 2.4; 95% CI: 1.2-4.6; P = .02) and were more likely to be nonambulatory on presentation (OR: 2.1; 95% CI: 1.0-4.1; P = .04). Dogs with EH were more likely to have <50% cross-sectional spinal cord compression than dogs without EH (OR: 2.3 vs. 0.4; 95% CI: 1.2-4.4 and 0.2-0.9, respectively), longer longitudinal spinal cord compression (3 spaces vs 1 space, P < .001), and greater intrinsic spinal cord change (grade 3/severe vs grade 1/mild; P < .001) based on MRI. The location of the intervertebral disc herniation in French Bulldogs with EH was more likely to be thoracolumbar (OR: 10.8; 95% CI: 2.1-55.7; P = .03). Conclusions and clinical importance: French Bulldogs have a high prevalence of intervertebral disc-associated EH. Dogs with EH have a shorter clinical course and are more likely to be nonambulatory on initial presentation.
An 11‐year‐old, female, neutered labrador retriever with a history of chronic and progressive right hindlimb lameness and facial asymmetry was referred for brain and lumbosacral magnetic resonance imaging and cerebrospinal fluid analysis. Multifocal non‐enhancing T2‐weighted images of hyperintense lesions were observed in the caudate nuclei and medulla oblongata. The right oculomotor nerve was markedly enlarged and showed marked enhancement on T1‐weighted images after contrast injection, and there was diffuse enlargement of the sciatic and femoral nerves in the right hindlimb. Cerebrospinal fluid analysis showed a mixed pleocytosis. Histopathology revealed granulomatous inflammation affecting the brain, oculomotor and pelvic limb nerves, consistent with a diagnosis of granulomatous meningoencephalomyelitis.
To investigate emergency clinicians’ comfort level in assessing neurological emergencies and to identify opportunities to foster enhanced training of clinical neurology in the emergency room. Internet‐based survey. University teaching hospitals and private referral centers. One hundred and ninety‐two emergency and critical care specialists and resident trainees (ECC) and 104 neurology specialists and resident trainees (NEUR) in clinical practice. An internet‐based survey was distributed via veterinary professional organizations’ listserves and message boards and responses were collected between March and April 2020. ECC completed a survey evaluating stress levels associated with neurological emergencies, confidence with neurological examinations, and neuroanatomical localization. NEUR completed a similar survey to report their perception of their ECC colleagues’ confidence in the assessment of neurological cases. Chi‐square and Mann–Whitney U‐tests were used to compare categorical responses and confidence scores between groups. P < 0.002 was considered significant. Fifty‐two percent of ECC found neurological emergencies slightly challenging, whereas 85% of NEUR found them moderately to extremely challenging for ECC (P < 0.0001). ECC's median self‐reported confidence score in performing a neurologic examination on a scale of 0–100 was 75 (interquartile range [IQR], 27), while NEUR reported a median ECC confidence of 44 (IQR, 25; P < 0.0001). Median self‐reported ECC confidence in localizing intracranial, spinal, and neuromuscular disease was 67 (IQR, 40), 88 (IQR, 21), and 60 (IQR, 37), respectively, which was significantly higher than median NEUR‐reported ECC confidence of 35 (IQR, 38), 51 (IQR, 31), and 18 (IQR, 20), respectively (all P < 0.0001). Following case transfer, 34% of ECC received NEUR feedback in >75% of cases. Noticeable discrepancies between ECC and NEUR perceptions of ECC clinical confidence were seen, while no firm evidence of neurophobia could be inferred. Improvements in interdepartmental communication and teaching of clinical neurology may be warranted.
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Background: Congenital sensorineural deafness (CSD) is the most common type of deafness in dogs and it occurs in numerous canine breeds including the English bull terrier. This study estimates prevalence, heritability and genetic correlations of CSD and coat pigmentation phenotypes in the English bull terrier in England. Results: Hearing status was assessed by brainstem auditory evoked response in 1060 English bull terrier puppies tested at 30-78 (mean 43.60) days of age as complete litters. Gender, coat and iris colour and parental hearing status were recorded. The prevalence of CSD in all 1060 puppies was 10.19 % with 8.21 % unilaterally deaf and 1.98 % bilaterally deaf. The coat was predominately coloured in 49.15 % puppies and white with or without a patch in 50.85 % puppies. The majority (96.29 %) of deaf puppies had a white coat (with or without a patch); 19.29 % of the puppies with a white coat (with or without a patch) were deaf. Heritability and genetic correlations were estimated using residual maximum likelihood. Heritability of hearing status as a trichotomous trait (bilaterally normal/unilaterally deaf/bilaterally deaf) was estimated at 0.15 to 0.16 and was significantly different to zero (P < 0.01). Heritability of coat pigmentation phenotype (all white/white with patches/coloured) was 0.49 (standard error 0.077). Genetic correlation of CSD with coat pigmentation phenotype was estimated at -0.36 to -0.37 (CSD associated with all white coat), but was not significantly larger than zero (P > 0.05). Analysis of CSD in all white and white patched puppies only estimated the heritability of CSD as 0.25 and was significantly greater than zero (P < 0.01), and the heritability of coat colour (all white/white with patches) as 0.20 (standard error 0.096). The genetic correlation was estimated at -0.53 to -0.54 (CSD associated with all white coat) but was just above the statistical threshold determining significant difference to zero (P = 0.06). Conclusions: These results indicate that CSD occurs predominantly in white English bull terriers and there is genetic variation in CSD beyond that associated with coat colour.
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This article outlines the consensus proposal on diagnosis of epilepsy in dogs by the International Veterinary Epilepsy Task Force. The aim of this consensus proposal is to improve consistency in the diagnosis of epilepsy in the clinical and research settings. The diagnostic approach to the patient presenting with a history of suspected epileptic seizures incorporates two fundamental steps: to establish if the events the animal is demonstrating truly represent epileptic seizures and if so, to identify their underlying cause. Differentiation of epileptic seizures from other non-epileptic episodic paroxysmal events can be challenging. Criteria that can be used to make this differentiation are presented in detail and discussed. Criteria for the diagnosis of idiopathic epilepsy (IE) are described in a three-tier system. Tier I confidence level for the diagnosis of IE is based on a history of two or more unprovoked epileptic seizures occurring at least 24 h apart, age at epileptic seizure onset of between six months and six years, unremarkable inter-ictal physical and neurological examination, and no significant abnormalities on minimum data base blood tests and urinalysis. Tier II confidence level for the diagnosis of IE is based on the factors listed in tier I and unremarkable fasting and post-prandial bile acids, magnetic resonance imaging (MRI) of the brain (based on an epilepsy-specific brain MRI protocol) and cerebrospinal fluid (CSF) analysis. Tier III confidence level for the diagnosis of IE is based on the factors listed in tier I and II and identification of electroencephalographic abnormalities characteristic for seizure disorders. The authors recommend performing MRI of the brain and routine CSF analysis, after exclusion of reactive seizures, in dogs with age at epileptic seizure onset <6 months or >6 years, inter-ictal neurological abnormalities consistent with intracranial neurolocalisation, status epilepticus or cluster seizure at epileptic seizure onset, or a previous presumptive diagnosis of IE and drug-resistance with a single antiepileptic drug titrated to the highest tolerable dose. This consensus article represents the basis for a more standardised diagnostic approach to the seizure patient. These recommendations will evolve over time with advances in neuroimaging, electroencephalography, and molecular genetics of canine epilepsy. Electronic supplementary material The online version of this article (doi:10.1186/s12917-015-0462-1) contains supplementary material, which is available to authorized users.
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Spinal disease in dogs is commonly encountered in veterinary practice. Numerous diseases may cause similar clinical signs and presenting histories. The study objective was to use statistical models to identify combinations of discrete parameters from the patient signalment, history and neurological examination that could suggest the most likely diagnoses with statistical significance. A retrospective study of 500 dogs referred to the Queen Mother Hospital for Animals before June 2012 for the investigation of spinal disease was performed. Details regarding signalment, history, physical and neurological examinations, neuroanatomical localisation and imaging data were obtained. Univariate analyses of variables (breed, age, weight, onset, deterioration, pain, asymmetry, neuroanatomical localisation) were performed, and variables were retained in a multivariate logistic regression model if P<0.05. Leading diagnoses were intervertebral disc extrusion (IVDE, n=149), intervertebral disc protrusion (n=149), ischaemic myelopathy (IM, n=48) and neoplasms (n=44). Multivariate logistic regression characterised IM and acute non-compressive nucleus pulposus extrusions as the only peracute onset, non-progressive, non-painful and asymmetrical T3-L3 myelopathies. IVDE was most commonly characterised as acute onset, often deteriorating, painful and largely symmetrical T3-L3 myelopathy. This study suggests that most spinal diseases cause distinctive combinations of presenting clinical parameters (signalment, onset, deterioration, pain, asymmetry, neuroanatomical localisation). Taking particular account of these parameters may aid decision making in a clinical setting. British Veterinary Association.
Congenital vertebral malformations are common incidental findings in small breed dogs. This retrospective observational study evaluated the type and prevalence of thoracic vertebral malformations in 171 neurologically normal and 10 neurologically abnormal screw-tailed brachycephalic dogs. Neurologically normal dogs underwent CT for reasons unrelated to spinal disease, while affected dogs underwent MRI. Imaging studies were reviewed and vertebral malformations including hemivertebrae, block vertebrae, transitional vertebrae, and spina bifida were documented. The group of clinically normal dogs consisted of 62 French bulldogs, 68 Pugs and 41English bulldogs. The group of affected dogs consisted of one French bulldog and nine Pugs. Overall, 80.7% of neurologically normal animals were affected by at least one vertebral malformation. There was a significant influence of breed, with thoracic vertebral malformations occurring more often in neurologically normal French bulldogs (P<0.0001)and English bulldogs (P=0.002). Compared to other breeds, hemivertebrae occurred more often in neurologically normal French bulldogs (93.5%; P< 0.0001 vs. Pugs; P=0.004 vs. English bulldogs) and less often in neurologically normal Pugs (17.6%; P=0.004 vs. English bulldogs). Neurologically normal Pugs were more often diagnosed with transitional vertebrae and spina bifida compared to other breeds (P<0.0001 for both malformations). Of Pugs included in the study, 4.7% were diagnosed with clinically relevant thoracic vertebral malformations. When compared to the general veterinary hospital population, this was significantly more than the other two breeds (P= 0.006). This study indicates that thoracic vertebral malformations occur commonly in neurologically normal screw-tailed brachycephalic dogs. While hemivertebrae are often interpreted as incidental diagnostic findings, they appear to be of greater clinical importance in Pugs compared to other screw- tailed brachycephalic breeds.
OBJECTIVE To determine the incidence of and risk factors for development of postop- erative diskospondylitis (POD) in dogs that underwent spinal decompression surgery for intervertebral disk herniation (IVDH). DESIGN Retrospective single cohort study. ANIMALS 372 dogs that underwent spinal decompression surgery for IVDH between January 2007 and January 2011. PROCEDURES Medical records of dogs were retrospectively reviewed. Data regarding signal- ment, type and anatomic site of IVDH, severity of neurologic signs, type of surgery, duration of anesthesia, esophageal temperature during surgery, and use of corticosteroid drugs were analyzed for associations with POD. RESULTS POD developed in 8 of 372 (2.2%) dogs. Univariate analysis revealed that German Shepherd Dogs had 9.8 times the odds of POD, compared with the odds for other breeds. In addition, dogs > 8.8 years of age, weighing > 20 kg (44 lb), or having disk protrusions were at higher risk of developing POD than were other dogs.The only factor that retained a signi cant association with POD after controlling for other factors in multivariate analysis was body weight > 20 kg. CONCLUSIONS AND CLINICAL RELEVANCE Factors identi ed in this study may be useful for prediction of POD, an appar- ently uncommon outcome, in dogs undergoing spinal decompression surgery for IVDH. Dogs at higher risk than others, particularly those weighing > 20 kg, should be monitored carefully in the immediate postoperative period, and signs of worsening neurologic condition after initial improvement should be promptly investigated.
Although several studies indicate that meningoencephalitis of unknown aetiology (MUA) might affect every dog breed at every age, little is known about clinical presentation, diagnostic findings and long-term survival in large breed dogs. The aim of this study was therefore to compare the clinical presentation, diagnostic findings and long-term survival between large and small/medium breed dogs diagnosed with MUA. One hundred and eleven dogs met the inclusion criteria. 28 (25 per cent) dogs were considered large breed dogs compared with 83 (75 per cent) small/medium breed dogs. Large breed dogs presented significantly more often with a decreased mentation. Age, gender, duration of clinical signs prior to diagnosis, presence of seizures or cluster seizures, variables on complete blood count and cerebrospinal fluid analysis, and all variables on MRI were not significantly different between small/medium and large breed dogs. Median survival time was 281 and 106 days for the large and small/medium breed dogs, respectively, with no significant difference in survival curves for both groups. Although considered not typically affected by MUA, 25 per cent of dogs included in this study were considered large breed dogs. Therefore, MUA should be included in the differential diagnosis for large breed dogs presenting with intracranial neurological signs. If diagnosed with MUA, large breed dogs also carried a guarded prognosis.
Treatment recommendations differ for dogs with intervertebral disk extrusion vs. intervertebral disk protrusion. The aim of this retrospective, cross-sectional study was to determine whether clinical and magnetic resonance imaging (MRI) variables could be used to predict a diagnosis of thoracolumbar intervertebral disk extrusion or protrusion in dogs. Dogs were included if they were large breed dogs, had an MRI study of the thoracolumbar or lumbar vertebral column, had undergone spinal surgery, and had the type of intervertebral disk herniation (intervertebral disk extrusion or protrusion) clearly stated in surgical reports. A veterinary neurologist unaware of surgical findings reviewed MRI studies and recorded number, location, degree of degeneration and morphology of intervertebral disks, presence of nuclear clefts, disk space narrowing, extent, localization and lateralization of herniated disk material, degree of spinal cord compression, intraparenchymal intensity changes, spondylosis deformans, spinal cord swelling, spinal cord atrophy, vertebral endplate changes, and presence of extradural hemorrhage. Ninety-five dogs were included in the sample. Multivariable statistical models indicated that longer duration of clinical signs (P = 0.01), midline instead of lateralized disk herniation (P = 0.007), and partial instead of complete disk degeneration (P = 0.01) were associated with a diagnosis of intervertebral disk protrusion. The presence of a single intervertebral herniation (P = 0.023) and dispersed intervertebral disk material not confined to the disk space (P = 0.06) made a diagnosis of intervertebral disk extrusion more likely. Findings from this study identified one clinical and four MRI variables that could potentially facilitate differentiating intervertebral disk extrusions from protrusions in dogs.
Congenital malformations of the thoracic vertebral bodies are commonly encountered in veterinary practice. These anomalies are prevalent in juvenile and adult small-breed dogs. These anomalous vertebrae typically result in various degrees of kyphosis and scoliosis in the region of the abnormality. They are thought to occur following developmental errors during embryonic or fetal vertebral segmentation and ossification; most are incidental. This article focuses on those anomalies of the thoracic vertebral bodies that lead to clinical signs of neurologic dysfunction. Based on a limited number of reported cases, the prognosis for surgically managed dogs with thoracic vertebral body abnormalities is favorable.
Cystic lesions of the vertebral column and spinal cord are important differential diagnoses in dogs with signs of spinal cord disease. Synovial cysts are commonly associated with degenerative joint disease and usually affect the cervical and lumbosacral regions. Arachnoid diverticulum (previously known as cyst) is seen in the cervical region of large breed dogs and thoracolumbar region of small breed dogs. This article reviews the causes, diagnosis, and treatment of these and other, less common, cystic lesions.
Objective: To identify characteristics of chondrodystrophoid and nonchondrodystrophoid small-breed dogs with cervical intervertebral disk herniation (IVDH). Design: Retrospective case series. Animals: 187 small-breed (≤ 15 kg [33 lb]) dogs that underwent surgery because of cervical IVDH. Procedures: Medical records were reviewed for information on breed, sex, age, weight, location of affected intervertebral disks, duration and severity of neurologic signs, and recovery time. Results: 55 of the 187 (29.4%) dogs were Beagles. The most frequently affected intervertebral disk was C2-3 (81/253 [32.0%]), and this was the more frequently affected intervertebral disk in dogs of several chondrodystrophoid breeds, including Beagles (29/66 [43.9%]), Dachshunds (13/37 [35.1%]), Shih Tzus (16/41 [39.0%]), and Pekingese (3/10 [30.0%]). However, caudal disks (C5-6 or C6-7) were more frequently affected in Yorkshire Terriers (13/24 [54.2%]) and Chihuahuas (9/13 [69%]). Shih Tzus and Yorkshire Terriers were significantly older at the time of surgery (mean ± SD age, 9.6 ± 2.3 years and 9.5 ± 2.5 years, respectively) than were Pomeranians (6.2 ± 2.3 years), and Yorkshire Terriers had a significantly higher number of affected disks (2.0 ± 0.9) than did Dachshunds (1.1 ± 0.3). Mean recovery time was significantly longer in Yorkshire Terriers (36.7 ± 13.0 days) than in Beagles (16.5 ± 17.1 days), Shih Tzus (17.8 ± 14.5 days), or Chihuahuas (12.2 ± 7. 2 days). Conclusions and clinical relevance: Results suggested that there may be breed-specific differences in the characteristics of cervical IVDH in small-breed dogs.