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Proportion of litters of purebred dogs born by caesarean section

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To describe the frequency of caesarean sections in a large sample of pedigree dogs in the UK. Data on the numbers of litters born in the previous 10 years were available from a cross-sectional study of dogs belonging to breed club members (2004 Kennel Club/BSAVA Scientific Committee Purebred Dog Health Survey). In this survey 151 breeds were represented with data for households that had reported on at least 10 litters (range 10-14,15): this represented 13,141 bitches which had whelped 22,005 litters. The frequency of caesarean sections was estimated as the percentage of litters that were reported to be born by caesarean section (caesarean rates) and are reported by breed. The dogs were categorised into brachycephalic, mesocephalic and dolicocephalic breeds. The 10 breeds with the highest caesarean rates were the Boston terrier, bulldog, French bulldog, mastiff, Scottish terrier, miniature bull terrier, German wirehaired pointer, Clumber spaniel, Pekingese and Dandie Dinmont terrier. In the Boston terrier, bulldog and French bulldog, the rate was > 80%. These data provide evidence for the need to monitor caesarean rates in certain breeds of dog.
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PAPER
Journal of Small Animal Practice • Vol 51 • February 2010 • © 2010 British Small Animal Veterinary Association 113
INTRODUCTION
Statistics on caesarean sections in dogs are
difficult to come by. There is anecdotal
evidence that brachycephalic dogs are
more likely to need a caesarean section,
most likely because of a mismatch between
the bitch’s pelvic size and the size of the
puppies’ heads. A small study in Sweden
looked at 40 whelpings in 20 Boston ter-
riers and found that dystocia was more
likely to occur with increasing cranial cir-
cumference of the pups (Eneroth and oth-
ers 1999). It has also been suggested that a
significant proportion of pregnant brachy-
cephalic bitches undergo elective caesare-
ans before natural parturition begins.
A retrospective, longitudinal study in
Sweden using insurance data from 1995
to 2002 which included 195,931 bitches
found that the risk of dystocia was high-
est in the Scottish terrier, Chihuahua,
Pomeranian, pug and Staffordshire bull
terrier, and 63·8% of dystocic bitches
underwent emergency caesarean section
(Bergström and others 2006). The authors
pointed out that the Boston terrier, Eng-
lish bulldog and French bulldog were not
represented in their database as caesarean
section is not covered by the insurance
company in these breeds. Moreover, the
database included all insured bitches, not
just those that were pregnant.
The caesarean rate in humans has
been reported to be approximately 24%
of all births in England in 2006 to 2007
(National Health Service 2008) or 31·8%
of all births in the USA in 2007 ( Hamilton
and others 2009). Of course, there are
significant differences between dogs and
humans in terms of anatomy, reproduc-
tion and medical care among many other
factors.
To clarify which breeds of dog are
brachycephalic, we considered the skull
classification system (Evans and Chris-
tensen 1979). Skulls are classified accord-
ing to the ratio of the length of the facial
skeleton to the length of the cranial cavity.
The three categories are:
1. Mesocephalic – the facial skeleton is
the same length as the cranial cavity,
for example Labrador.
2. Brachycephalic – the facial skeleton is
relatively short compared to the cra-
nial cavity, for example bulldog.
3. Dolicocephalic – the facial skeleton is
relatively long compared to the cra-
nial cavity, for example greyhound.
The purpose of this study was to
describe the frequency of occurrence of
caesarean sections in a large sample of ped-
igree dogs in the UK, which were included
in the 2004 Kennel Club/ BSAVA Scien-
tific Committee Purebred Dog Health
Survey.
MATERIALS AND METHODS
Data on the numbers of litters born in
the previous 10 years were available from
a cross-sectional study of pedigree dogs
in the UK (Adams and others 2010).
OBJECTIVES: To describe the frequency of caesarean sections in a
large sample of pedigree dogs in the UK.
METHODS: Data on the numbers of litters born in the previous 10 years
were available from a cross-sectional study of dogs belonging to breed
club members (2004 Kennel Club/BSAVA Scientific Committee
Purebred Dog Health Survey). In this survey 151 breeds were repre-
sented with data for households that had reported on at least 10 litters
(range 10–14,15): this represented 13,141 bitches which had whelped
22,005 litters. The frequency of caesarean sections was estimated as
the percentage of litters that were reported to be born by caesarean
section (caesarean rates) and are reported by breed. The dogs were cat-
egorised into brachycephalic, mesocephalic and dolicocephalic breeds.
RESULTS: The 10 breeds with the highest caesarean rates were the
Boston terrier, bulldog, French bulldog, mastiff, Scottish terrier,
miniature bull terrier, German wirehaired pointer, Clumber spaniel,
Pekingese and Dandie Dinmont terrier. In the Boston terrier, bulldog
and French bulldog, the rate was > 80%.
CLINICAL SIGNIFICANCE: These data provide evidence for the need to
monitor caesarean rates in certain breeds of dog.
Proportion of litters of purebred dogs
born by caesarean section
KATY M. EVANS AND VICKI J. ADAMS
Journal of Small Animal Practice (2010)
51, 113–118
DOI: 10.1111/j.1748-5827.2009.00902.x
Accepted: 17 November 2009
Animal Health Trust, Lanwades Park, Kentford,
Newmarket, Suffolk CB8 7UU
114 Journal of Small Animal Practice • Vol 51 • February 2010 • © 2010 British Small Animal Veterinary Association
K. M. Evans & V. J. Adams
In brief, this survey gathered data on
dogs from 170 breeds recognised by The
Kennel Club (KC) and was administered
via breed club secretaries. Owners were
sent a questionnaire with a prepaid reply
envelope and were asked to complete it
anonymously for all dogs they owned of
the breed for which the breed club had
sent them the questionnaire. The ques-
tionnaire contained three sections per-
taining to the health status of all dogs
including questions covering the body sys-
tems, breeding of females and occurrence
of birth defects. A fourth section dealt
with dogs that had died in the previous
10 years. The questionnaire was designed
and pretested in two breeds, the Norfolk
terrier and German Spitz. Section B con-
tained seven questions on the breeding
history of all dogs owned and bred in the
previous 10 years of which the questions
“How many litters have your female dogs
had in total?” and “How many litters were
delivered by caesarean section?” were used
in this study. The questionnaire is avail-
able on the KC website (The Kennel Club
2006). Data were available for 36,006
live dogs of 169 breeds (as the German
Shepherd Breed Club did not participate)
and owners reported reproductive condi-
tions as open-ended responses in the first
section of the questionnaire.
In this analysis, 151 breeds were
included on which data were available
for at least 10 litters (range 10 to 1415):
this represented 13,141 bitches which had
whelped 22,005 litters. The frequency
of occurrence of caesarean sections was
estimated as the percentage of litters that
were reported to be born by caesarean sec-
tion, and these are referred to as caesarean
rates for each breed. The skull classifica-
tion system outlined above was used to
categorise the dogs into brachycephalic,
mesocephalic and dolicocephalic breeds.
The data were analysed using Excel (2002,
Microsoft Corporation).
RESULTS
The response rate to the survey was
24% (Adams and others 2010). There
were seven breeds for which there were
no reported caesareans (Table 1). These
were the Australian silky terrier, curly
coated retriever, German Pinscher,
Hamiltonstovare, Irish terrier, pharaoh
hound and Portuguese water dog. The
10 breeds with the highest caesarean rates
were the Boston terrier, bulldog, French
bulldog, mastiff, Scottish terrier, min-
iature bull terrier, German wirehaired
pointer, Clumber spaniel, Pekingese and
Dandie Dinmont terrier.
From the reporting of disease occur-
rence in the first section of the 2004
survey, reproductive conditions were the
most commonly reported overall and for
many individual breeds (The Kennel Club
2006). Dystocia was the third most com-
monly reported reproductive problem after
pyometra and false pregnancy. Five breeds,
French bulldog, King Charles spaniel,
Norfolk terrier, Norwich terrier and York-
shire terrier, were reported to have more
bitches that had suffered from dystocia
due to physical blockage than due to uter-
ine inertia. Nine breeds, Affenpinscher,
beagle, Boston terrier, Bullmastiff, Clum-
ber spaniel, deerhound, Irish wolfhound,
Labrador retriever and Scottish terrier,
were reported to have more bitches that
suffered from uterine inertia than physi-
cal blockage. Seven breeds, Border collie,
bull terrier, bulldog, Chihuahua, Dandie
Dinmont terrier, Pekingese and St Bernard
were reported to have approximately equal
numbers of bitches that suffered from
physical blockage and uterine inertia.
DISCUSSION
A multi-centre, prospective case series
studying dogs undergoing caesarean sec-
tion in the USA and Canada was under-
taken between 1994 and 1997 (Moon
and others 1998). The five most common
breeds to require emergency caesarean sec-
tion were the bulldog, Labrador retriever,
boxer, Corgi and Chihuahua, while the
five breeds most commonly undergoing
elective caesarean section were the bull-
dog, Labrador retriever, mastiff, Golden
retriever and Yorkshire terrier. In 1997 the
Labrador retriever and golden retriever
were both in the top four dog breeds
registered with the American KC, so the
authors felt that they were present in the
list of breeds most commonly undergoing
caesarean section as a result of their large
populations. However they concluded
that, as boxers and bulldogs were among
the most common breeds to undergo sur-
gery on an emergency basis, brachycephalic
breeds are predisposed to the development
of dystocia. Unfortunately it was impos-
sible to differentiate between emergency
and elective caesarean sections from the
data collected in the Purebred Dog Health
Survey. Despite this, the bulldog, Welsh
Corgi Pembroke, Chihuahua and mastiff
also had a high caesarean rate in the pres-
ent study, with the bulldog being the only
breed which had also been reported to be
in the top five breeds requiring both emer-
gency and elective caesarean section in the
North American study. Recall bias is a
potential limitation in this study as own-
ers were asked for information relating to
the breeding of bitches within the past
10 years. Nevertheless, owners appeared
to be able to provide the information
requested.
In the Swedish study of insured dogs,
the Scottish terrier was found to be the
breed at highest risk of dystocia, with an
incidence rate of 38·3 cases per 1000 dog
years (Bergström and others 2006). It
should be noted that the Boston terrier,
English bulldog and French bulldog were
not represented in the Swedish database.
Our data suggest that this may also be
the case for UK Scottish terriers as they
had the highest caesarean rate of all non-
brachycephalic breeds, at 60%. It has been
reported that some Scottish terriers have a
dorso-ventrally flattened pelvic canal that
increases the risk of obstructive dystocia
and the need for emergency caesarean sec-
tion (Eneroth and others 1999). However,
the data for UK bitches suggest that uter-
ine inertia may also be a problem in this
breed (The Kennel Club 2006).
A study of feline dystocia found that
cranial conformation was significantly
associated with dystocia (Gunn-Moore
and Thrusfield 1995). Interestingly, both
dolicocephalic and brachycephalic types
had a higher litter prevalence of dystocia
than mesocephalic cats, with the highest
prevalence occurring in dolicocephalic
breeds such as the Siamese. The present
data suggest that the dolicocephalic breeds
of dog may not have a higher occurrence
of dystocia compared to brachycephalic or
mesocephalic breeds.
Journal of Small Animal Practice • Vol 51 • February 2010 • © 2010 British Small Animal Veterinary Association 115
Proportion of litters of purebred dogs
Table 1. Number of litters reported and proportion born by caesarean section for 151 breeds for which data from the
2004 Purebred Dog Health Survey was available for 10 or more litters of puppies
Breed No. of forms No. of dogs No. of litters
Caesarean sections
Number %
Affenpinscher 22 69 131 32 24·4
Afghan hound 23 50 61 13 21·3
Airedale terrier 25 71 127 22 17·3
Akita 13 24 49 5 10·2
Alaskan Malamute 10 14 20 7 35
American cocker spaniel 24 56 83 9 10·8
Australian cattle dog 9 22 35 9 25·7
Australian shepherd 8 26 56 1 1·8
Australian silky terrier 3 7 11 0 0
Australian terrier 4 13 22 1 4·5
Basenji 12 28 34 5 14·7
Basset Fauve de Bretagne 9 19 33 4 12·1
Basset hound 32 76 116 41 35·3
Beagle 74 187 312 66 21·2
Bearded collie 78 165 264 19 7·2
Bedlington terrier 30 72 164 10 6·1
Belgian shepherd 33 69 100 11 11
Bernese mountain dog 64 181 281 72 25·6
Bichon frise 13 69 142 8 5·6
Bloodhound 11 34 42 4 9·5
Border collie 51 134 227 24 10·6
Border terrier 94 297 542 95 17·5
Borzoi 17 30 36 5 13·9
Boston terrier 14 43 52 48 92·3
Bouvier des Flandres 12 26 39 8 20·5
Boxer 45 150 283 50 17·7
Briard 20 35 47 14 29·8
Brittany 17 35 57 10 17·5
Bull terrier 50 113 186 43 23·1
Bulldog/British bulldog 71 195 288 248 86·1
Bullmastiff 29 61 82 29 35·4
Cairn terrier 34 140 251 43 17·1
Canaan Dog 2 10 16 1 6·3
Cavalier King Charles spaniel 201 670 1207 158 13·1
Cesky terrier 3 13 18 4 22·2
Chesapeake Bay retriever 15 49 103 7 6·8
Chihuahua 17 137 262 90 34·4
Chinese Crested 9 21 37 4 10·8
Chow Chow 20 71 135 38 28·1
Clumber spaniel 17 44 62 28 45·2
English cocker spaniel 131 472 802 81 10·1
Collie 27 119 171 19 11·1
Curly coated retriever 13 21 28 0 0
Dachshund 72 305 504 157 31·2
Dalmatian 89 175 291 46 15·8
Dandie Dinmont terrier 20 43 70 29 41·4
Deerhound 55 110 153 43 28·1
Dobermann 28 57 93 10 10·8
Dogue de Bordeaux 9 11 18 5 27·8
English setter 69 195 270 60 22·2
English springer spaniel 49 118 195 20 10·3
English toy terrier 13 39 68 7 10·3
Field spaniel 21 46 60 5 8·3
Finnish Lapphund 6 12 18 3 16·7
Finnish Spitz 12 26 37 9 24·3
Flatcoated retriever 153 277 398 54 13·6
Fox terrier 24 67 126 19 15·1
French bulldog 24 53 80 65 81·3
116 Journal of Small Animal Practice • Vol 51 • February 2010 • © 2010 British Small Animal Veterinary Association
K. M. Evans & V. J. Adams
Table 1. Number of litters reported and proportion born by caesarean section for 151 breeds for which data from the
2004 Purebred Dog Health Survey was available for 10 or more litters of puppies
Breed No. of forms No. of dogs No. of litters
Caesarean sections
Number %
German Pinscher 10 16 25 0 0
German shorthaired pointer 74 144 245 25 10·2
German Spitz 35 91 156 33 21·2
German wirehaired pointer 11 19 23 11 47·8
Giant schnauzer 12 29 51 6 11·8
Glen of Imaal terrier 8 13 16 3 18·8
Golden retriever 278 779 1415 250 17·7
Gordon setter 49 115 183 17 9·3
Great Dane 32 90 140 38 27·1
Greyhound 13 29 37 14 37·8
Griffon Bruxellois 23 53 82 32 39
Hamiltonstovare 4 9 13 0 0
Havanese 4 11 22 2 9·1
Hungarian Puli 8 19 29 5 17·2
Hungarian Vizsla 18 40 68 8 11·8
Hungarian Wirehaired Viszla 13 24 40 5 12·5
Irish red & white setter 44 97 144 15 10·4
Irish setter 115 238 343 38 11·1
Irish terrier 7 18 28 0 0
Irish water spaniel 24 49 73 4 5·5
Irish wolfhound 20 58 77 31 40·3
Italian greyhound 19 45 71 7 9·9
Italian Spinone 21 33 46 13 28·3
Japanese Chin 13 44 83 12 14·5
Japanese Spitz 7 17 35 1 2·9
Keeshond 25 63 90 11 12·2
Kerry Blue terrier 7 18 27 4 14·8
King Charles spaniel 15 52 78 17 21·8
Labrador retriever 197 492 866 175 20·2
Lagotto Romagnolo 3 5 12 1 8·3
Lakeland terrier 12 26 53 12 22·6
Lancashire Heeler 16 32 57 4 7
Large Munsterlander 17 30 35 7 20
Leonberger 22 48 72 17 23·6
Lhasa apso 37 130 216 29 13·4
Lowchen 10 54 108 8 7·4
Maltese 17 50 95 20 21·1
Manchester terrier 27 48 84 13 15·5
Maremma sheepdog 5 9 16 3 18·8
Mastiff 19 52 79 51 64·6
Miniature bull terrier 12 27 42 22 52·4
Miniature Pinscher 12 24 42 2 4·8
Miniature poodle 20 54 113 6 5·3
Miniature schnauzer 55 160 289 62 21·5
Neopolitan mastiff 3 7 11 4 36·4
Newfoundland 41 79 110 16 14·5
Norfolk terrier 77 181 324 56 17·3
Norwegian elkhound 15 33 56 6 10·7
Norwich terrier 24 78 134 49 36·6
Old English sheepdog 25 59 88 14 15·9
Otterhound 6 23 31 3 9·7
Papillon 44 106 189 33 17·5
Parson Russell terrier 23 81 165 37 22·4
Pekingese 20 101 178 78 43·8
Pharoah hound 5 8 10 0 0
Pointer 50 119 173 45 26
Polish lowland sheepdog 7 10 15 3 20
Pomeranian 16 87 168 37 22
Portuguese water dog 1 6 11 0 0
Journal of Small Animal Practice • Vol 51 • February 2010 • © 2010 British Small Animal Veterinary Association 117
Proportion of litters of purebred dogs
Breed No. of forms No. of dogs No. of litters
Caesarean sections
Number %
Pug dog 50 142 223 61 27·4
Pyrenean mountain dog 21 34 38 11 28·9
Pyrenean sheepdog 2 6 14 1 7·1
Rhodesian ridgeback 52 102 173 11 6·4
Rottweiler 29 70 127 22 17·3
Saluki 22 49 54 8 14·8
Samoyed 53 119 222 52 23·4
Schipperke 12 26 47 13 27·7
Schnauzer (standard) 16 29 48 9 18·8
Scottish terrier 26 99 164 98 59·8
Sealyham terrier 6 9 10 4 40
Shar-Pei 16 58 111 3 2·7
Shetland sheepdog 109 333 640 93 14·5
Shiba Inu (Japanese) 7 19 27 2 7·4
Shih Tzu 32 100 171 36 21·1
Siberian husky 62 121 175 43 24·6
Skye terrier 14 29 36 2 5·6
Soft coated wheaten terrier 54 82 149 16 10·7
St Bernard 11 32 34 14 41·2
Staffordshire bull terrier 64 135 220 42 19·1
Standard poodle 44 108 189 21 11·1
Sussex spaniel 19 40 62 12 19·4
Swedish Vallhund 9 14 20 6 30
Tibetan spaniel 57 149 252 39 15·5
Tibetan terrier 31 92 177 18 10·2
Toy poodle 6 25 43 5 11·6
Weimaraner 76 133 207 13 6·3
Welsh Corgi Cardigan 15 36 64 14 21·9
Welsh Corgi Pembroke 33 130 199 71 35·7
Welsh springer spaniel 61 127 205 17 8·3
Welsh terrier 16 40 84 6 7·1
West Highland white terrier 54 166 366 69 18·9
Whippet 145 317 438 66 15·1
Yorkshire terrier 14 66 139 14 10·1
In humans, it is currently thought that
a caesarean rate of between 5 and 10%
seems to achieve the best outcomes for
the health of both mothers and neonates
and that a rate of greater than 15%, a fig-
ure recommended by the World Health
Organisation (WHO 1985), “seems to
result in more harm than good” (Alathabe
and Belizán 2006).
Some studies suggest that, in humans,
elective caesarean section offers no
real health advantages to either moth-
ers or neonates, and may actually carry
increased health risks compared with
vaginal delivery (Armson 2007). Howev-
er, it has been shown that there are fewer
complications associated with planned
caesarean sections than with unplanned,
emergency caesarean sections (Häger and
others 2004). If this situation is mirrored
in bitches, it could be suggested that
performing an elective caesarean section
is preferable to letting labour commence
and fail to progress. Leaving a bitch to
whelp unassisted can lead to the need
for an emergency caesarean section if it
is anticipated that the bitch is likely to
experience dystocia (due to previous dys-
tocia, size of sire or breeding history of
female relatives, as has been suggested
in humans (Tollanes and others 2008)).
However, this raises concerns about ani-
mal welfare – such as, should that bitch
have been mated (or mated with that
dog) at all? The authors understand that
The KC is seeking the support of veteri-
nary organisations in the UK on a pro-
posal to prevent the registration of a litter
if the dam has already produced two lit-
ters delivered by caesarean section.
The results of this study cannot neces-
sarily be generalised to all dogs because the
2004 health survey was a convenience sam-
ple rather than a random sample of the UK
pedigree dog population. However, this
large cross-sectional study provides evidence
that the caesarean section rates appear to be
high in several breeds. This study found
that five of the 10 breeds with the highest
reported caesarean rate were brachycephalic
breeds. Indeed in three breeds, the Boston
terrier, bulldog and French bulldog, the rate
was greater than 80%. These data provide
evidence for the need to monitor caesarean
rates in certain breeds of dog.
Acknowledgement
The authors would like to thank the
Kennel Club Charitable Trust for funding
this study.
118 Journal of Small Animal Practice • Vol 51 • February 2010 • © 2010 British Small Animal Veterinary Association
K. M. Evans & V. J. Adams
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... Control of the delivery process should be recommended when labour is delayed in order to decrease peri-parturient puppy mortality. These include administration of oxytocin and prostaglandins to increase myometrial contraction (Guyton & Hall, 2000), digital manipulation using forceps (Max and Jurka, 2013) and surgical delivery of the puppies through caesarean section (Evans & Adams, 2010). In a previous study, obstetrical manipulations and/or medical treatment was successful only in 27.6% of cases of dystocia in dogs, while surgical intervention was required in approximately 60-80% of dystocia cases in the bitches and queens (Bergstrom et al., 2006;. ...
... Caesarean rate in humans have been reported to be approximately 24% of all births in England and 31.8 % of all birth in the USA (Hamilton et al., 2008). However, statistics on caesarean sections in dogs are difficult to come by (Evans & Adams, 2010). Some breeds of dogs such as Boston terrier, Bull dogs have been reported to have high rate of caesarean section (Bergstrom et al., 2006;Evans & Adams, 2010). ...
... However, statistics on caesarean sections in dogs are difficult to come by (Evans & Adams, 2010). Some breeds of dogs such as Boston terrier, Bull dogs have been reported to have high rate of caesarean section (Bergstrom et al., 2006;Evans & Adams, 2010). Previous reports showed that 37.5% of bitches with dystocia in Nigeria were managed with caesarean section (Ajala & Fayemi, 2011). ...
... However, brachycephalic dogs are predisposed to inherited conformational disorders, which can result in lower blood oxygen (Packer et al., 2015;Canola et al., 2018) and even systemically healthy brachycephalic dogs were prone to have lower blood oxygen levels (Hoareau et al., 2012). Another characteristic of brachycephalic breeds is a high susceptibility to dystocia, with reports of caesarean indices higher than 80% (Bergstrom et al., 2006;Evans and Adams, 2010). Since parturition is a critical event (Beccaglia et al., 2016), appropriate caesarean management is essential to avoid either premature birth or intrauterine foetal suffering (Giannico et al., 2016). ...
... It is well known that foetal vascularisation is an indicator of nutrient and oxygen supply to the foetus (Nautrup, 1998;Di Salvo et al., 2006), consequently the RI of the umbilical artery (RIUA) is a good parameter to diagnosis foetal stress caused by disorders in placental blood flow and foetal hypoxia (Giannico et al., 2015). Currently, RIUA is assessed to determine the timing of parturition and foetal suffering (Beccaglia et al., 2016) and the evaluation of this parameter might be worthwhile in brachycephalic breeds, since brachycephalic bitches are more prone for dystocia and caesarean section (Bergstrom et al., 2006;Evans and Adams, 2010). ...
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Maternal brachycephaly only does not influence umbilical artery resistance in late canine pregnancy [A braquicefalia materna, isoladamente, não influencia a resistência da artéria umbilical no final da gestação em cães] "Scientific Article/Artigo Científico" Abstract The popularity of canine brachycephalic breeds is rising in many countries of the world. Brachycephalic dogs are predisposed to developing brachycephalic obstructive airway syndrome (BOAS), resulting in lower partial pressure of oxygen in the arterial blood which might influence foetal haemodynamic parameters. Therefore, this study aimed to evaluate the influence of the maternal morphological characteristic (brachycephaly) on the resistive index of the umbilical artery (RIUA) during late pregnancy. This was a non-randomized and cross-sectional study that included data of foetuses from 42 clinically healthy pregnant bitches. The RIUA was measured in 137 foetuses, from 68 and 69 brachycephalic and non-brachycephalic bitches, respectively, between the seventh to ninth weeks of pregnancy. Gestational age was determined by ultrasonography according to foetal biparietal diameter (BP) by measuring two to four foetuses/pregnant bitch. Female dogs with at least one foetus diagnosed with a consistent heart rate below 180 bpm were not included in the present study. There was a significant weekly decrease in the RIUA of foetuses from both brachycephalic and non-brachycephalic bitches, from the seventh until the last week of evaluation. No differences were detected in the RIUA ate the same gestational week between foetuses from brachycephalic and non-brachycephalic bitches. In conclusion, maternal brachycephaly only is not able to induces RIUA changes in canine foetuses during late pregnancy. Resumo A popularidade de raças braquicefálicas tem aumentado em vários países do mundo. Cães braquicefálicos são predispostos ao desenvolvimento da síndrome obstrutiva das vias aéreas (SOVA), causando a redução da pressão parcial de oxigênio no sangue arterial, o que pode influenciar parâmetros hemodinâmicos fetais. Dessa forma, objetivou-se com este estudo avaliar a influência da característica morfológica materna (braquicefalia) sobre o índice de resistividade da artéria umbilical (IRAU) no final da gestação. Trata-se de um estudo não randomizado, transversal, que incluiu os dados de fetos oriundos de 42 cadelas prenhas e clinicamente saudáveis. O IRAU foi mensurado em 137 fetos, entre a sétima e a nona semana de gestação, sendo 68 provenientes de cadelas braquicefálicas e 69 de cadelas não braquicefálicas. A idade gestacional foi estimada de acordo com o diâmetro biparietal (DBP) dos fetos, a partir da mensuração de dois a quarto fetos/cadela. Cadelas com pelo menos um feto diagnosticado com uma frequência cardíaca inferior a 180 bpm não foram incluídas no presente estudo. Foi observada uma redução semanal significativa nos valores do IRAU, tanto das cadelas braquicefálicas quanto das não-braquicefálicas, entre a sétima até a nona semana de gestação. Não foram detectadas diferenças no IRAU para a mesma semana de gestação entre fetos de cadelas braquicefálicas e não-braquicefálicas. Em conclusão, a braquicefalia, isoladamente, não é capaz de induzir alterações no IRAU dos fetos caninos no final da gestação. Palavras-chave: Doppler fetal; cordão umbilical; índice de resistividade; cães braquicefálicos. Sandes et al. (2021) Maternal brachycephaly only does not influence umbilical artery resistance…
... It is important to note that the Boerboel breed is over-represented in most of the reviewed studies in this manuscript and that it is at high odds, 0.54 (CI,n = 265), for CS . In another study, the proportion of litters born by CS in a very large sample (22,005 L from 151 breeds in the UK) was 19% (Evans & Adams, 2010). The results of the survey shown in Table 1 show that 38% of bitches required one or more CS during their reproductive lifetime . ...
... The results of the survey shown in Table 1 show that 38% of bitches required one or more CS during their reproductive lifetime . This percentage cannot be directly compared to the 19% of Evans and Adams (2010), because different methods to calculate the prevalence of CSs and different breeds were examined. ...
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... ✓ Spay or neuter. Females often have difficulty birthing and spaying or neutering prevents unwanted pregnancies (Evans and Adams, 2010). ...
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