ArticlePDF Available

Characteristics of compulsive tail chasing and associated risk factors in Bull Terriers

  • Animal Behavior Consultations, LLC


To evaluate and define the characteristics of tail chasing in Bull Terriers and explore the association between tail chasing and other behavioral and physical characteristics. Survey and case-control study. 333 Bull Terriers (145 dogs with tail-chasing behavior and 188 unaffected dogs). Owners of Bull Terriers with tail-chasing behavior were surveyed regarding the age of onset, triggers, frequency, duration, interruptability, degree of disruption to the dogs' normal functioning and the owners' relationship with the dog, and associated medical and physical consequences. Associations of tail chasing with various behavioral and physical characteristics were examined by comparison of dogs with tail-chasing behavior with unaffected dogs. Phenotypic and developmental descriptions of tail chasing in Bull Terriers were defined. Associations of tail chasing with sex, trance-like behavior, and episodic aggression were found. Males were at an 8% greater risk for the diagnosis of tail chasing than females. Phobias and owner-directed aggression did not significantly associate with tail chasing in the final log-linear model, but did have significant associations in earlier analyses that did not include the behaviors of episodic aggression and trance-like behavior. In Bull Terriers with tail-chasing behavior, there was a slight increase in the susceptibility of males to develop tail-chasing behavior, compared with females. A close association of tail chasing with trance-like behavior and episodic aggression was identified.
JAVMA, Vol 238, No. 7, April 1, 2011 Scientific Reports 883
Tail chasing is a repetitive behavior that is expressed
as slow to rapid circling with the dog’s attention di-
rected toward the tail or rapid spinning in tight circles
with no apparent focus on the tail. Within the same
dog, these 2 forms of expression (slow, focused; rapid,
unfocused) may be expressed interchangeably. Slow
chasing focused on the tail often precedes rapid unfo-
cused spinning bouts. In its most advanced stage, tail
chasing is a debilitating and potentially life-threatening
behavioral condition.
Classic tail chasing, which is frequently bidirec-
tional, is not caused by organic problems such as a brain
tumor, local irritation, or other medical conditions, and
neither is it typically an attention-seeking behavior.
Many dogs chase their tail when separated from their
owners, and when fully engaged in the behavior, the
dogs appear dissociated from their environment and re-
sistant to any form of interruption. They are often unre-
sponsive to their owner’s commands when in this state,
many shun their owner’s attention, and some become
aggressive when attempts to interrupt them are made.
Bull Terriers that are punished for tail chasing will often
remove themselves to a location remote from the owner
to engage in the behavior. Although tail chasing occurs
Characteristics of compulsive tail chasing
and associated risk factors in Bull Terriers
Alice A. Moon-Fanelli, phd; Nicholas H. Dodman, bvms; Thomas R. Famula, phd; Nicole Cottam, ms
Objective—To evaluate and define the characteristics of tail chasing in Bull Terriers and ex-
plore the association between tail chasing and other behavioral and physical characteristics.
Design—Survey and case-control study.
Animals—333 Bull Terriers (145 dogs with tail-chasing behavior and 188 unaffected dogs).
Procedures—Owners of Bull Terriers with tail-chasing behavior were surveyed regarding
the age of onset, triggers, frequency, duration, interruptability, degree of disruption to the
dogs’ normal functioning and the owners’ relationship with the dog, and associated medical
and physical consequences. Associations of tail chasing with various behavioral and physi-
cal characteristics were examined by comparison of dogs with tail-chasing behavior with
unaffected dogs.
Results—Phenotypic and developmental descriptions of tail chasing in Bull Terriers were
defined. Associations of tail chasing with sex, trance-like behavior, and episodic aggression
were found. Males were at an 8% greater risk for the diagnosis of tail chasing than females.
Phobias and owner-directed aggression did not significantly associate with tail chasing in
the final log-linear model, but did have significant associations in earlier analyses that did
not include the behaviors of episodic aggression and trance-like behavior.
Conclusions and Clinical Relevance—In Bull Terriers with tail-chasing behavior, there was
a slight increase in the susceptibility of males to develop tail-chasing behavior, compared
with females. A close association of tail chasing with trance-like behavior and episodic ag-
gression was identified. (J Am Vet Med Assoc 2011;238:883–889)
in a variety of breeds, it is most commonly observed in
Bull Terriers and German Shepherd Dogs.1,2
The disorder has previously been attributed to
opioid-mediated stereotypy3 or a seizure-related neu-
rologic syndrome phenomenon.4,5 The seizure-related
neurologic syndrome hypothesis suggests a putative
association between tail chasing and episodic aggres-
sion, trance-like behavior, hyperactivity, sound sensi-
tivity, and fear responses and phobias. It has also been
hypothesized that this neurologic syndrome has some
features in common with another disease in Bull Terri-
ers, lethal acrodermatitis.6 In addition to having derma-
tologic problems, dogs with lethal acrodermatitis may
have hydrocephalus and characteristic behavioral signs,
such as aggression and prolonged staring. Recent stud-
ies2,7–9 investigating the clinical signs, development,
and response to pharmacological treatment of tail chas-
ing in dogs support a compulsive etiology similar to hu-
man obsessive-compulsive disorder. The purpose of the
study reported here was to define and evaluate charac-
teristics of tail chasing in Bull Terriers and any associa-
tion with other physical and behavioral characteristics
as a preliminary step toward future investigation of the
inheritance of tail chasing in Bull Terriers.
Materials and Methods
Study participants—Dog owners for the study
were solicited through clients of Tufts University Cum-
mings School of Veterinary Medicine, the Bull Terrier
Club of America, Bull Terrier Welfare Foundation, lo-
cal dog shows, Silverwood National Bull Terrier Spe-
From the Department of Clinical Science, Cummings School of Veter-
inary Medicine, Tufts University, North Grafton, MA 01536 (Moon-
Fanelli, Dodman, Cottam); and the Department of Animal Science,
School of Veterinary Medicine, University of California-Davis, Da-
vis, CA 95616 (Famula). Dr. Moon-Fanelli’s present address is Ani-
mal Behavior Consultations LLC, Brooklyn Veterinary Hospital, PO
Box 285, Brooklyn, CT 06234.
884 Scientific Reports JAVMA, Vol 238, No. 7, April 1, 2011
cialty show, and the Bull Terrier Neurological Disorder
website. Convenience sampling methods were used
to increase the number of dogs included in the study.
Dogs were assigned to either the affected or unaffected
group on the basis of the presence or absence of tail
chasing as described by owners. All dogs included in
the study were examined by the owner’s local veterinar-
ian or evaluated at Tufts University Cummings School
of Veterinary Medicine. Most owners of Bull Terriers
with tail-chasing behavior had contacted a veterinarian
for treatment advice prior to participating in the study.
Owners of dogs with daily tail-chasing behavior typical-
ly requested medication to treat the condition because
of the severity and disruptive nature of the behavior. No
medical conditions associated with the onset or propa-
gation of tail chasing were reported. Owners completed
a research questionnaire that was designed to identify
those dogs affected with compulsive tail chasing as op-
posed to other conditions.
Survey—Owners of dogs with tail-chasing behav-
ior were sent a survey designed to solicit information
regarding the appearance of tail chasing, age of onset,
frequency of bouts, duration of bouts, and eliciting trig-
gers. Owners were asked to provide their best estimate
for age of onset and frequency and duration of tail chas-
ing bouts on the basis of their history of living with the
dog in the home. Questions regarding various physical
and behavioral conditions were also included in the sur-
vey. As new behavior patterns emerged over the 16-year
duration of data gathering, 2 additional questions were
added to assess the degree of interference that the dog’s
tail chasing caused regarding the dog’s quality of life and
the owner’s relationship with the dog. Subsequent study
participants were asked to report how the amount of
time the dog spent tail chasing interfered with its nor-
mal daily activities and relationship with the owner. The
owner was asked to score 0 for no interference, 1 for
slight interference, 2 for mild to moderate interference,
3 for definite interference that was still manageable, and
4 for interference that incapacitated every aspect of the
dog’s or owner’s life. When responses were unclear, own-
ers were contacted directly for clarification.
For comparative purposes, sex and neuter status
as well as behavioral data were collected for all Bull
Terriers in the study regardless of whether they had
tail-chasing behavior. Owner-directed aggression was
assessed by having owners complete a previously pub-
lished checklist indicating interactions in which their
dog might challenge them, including but not limited
to resource guarding, routine handling, and mild re-
straint.10 Owner-directed aggression included behaviors
of growling, lift lip, snapping, or biting. Episodic ag-
gression was defined as recurrent, unprovoked attacks
directed toward people, other animals, or objects in the
household. The attacks are explosive, violent, sudden,
and unpredictable, with little to no provocation and no
typical warning signals. The behavior is out of character
for the dog’s normal demeanor. An awake but peaceful
dog may have a transition state, often of quite short du-
ration, in which the eyes glaze, followed by an attack.
Statistical analysis—The survey was designed to
evaluate dogs on a large set of binary random variables,
among these being tail-chasing behavior (yes or no), sex
(male or female), coat color (white or other color), and
a list of other behavioral variables. Data were analyzed
in accordance with the concept of log-linear models.11
By use of this approach, tail chasing was considered as
just another observed binary random variable (ie, tail
chasing was not considered as caused by the action of
other variables). The count of dogs was evaluated in
cross-sectional tables to evaluate whether tail-chasing
behavior is observed independent of other behaviors,
sex, or coat colors. The modeled variable was thus a
count, not the presence or absence of tail chasing; the
count of dogs was classified by sex, coat color, tail chas-
ing status, and all other binary behavior observations.
The first step in this analysis was to estimate the
correlation between all the assembled elements of the
survey. Being binary characters, the polychoric correla-
tion12 was computed by use of a software program of
the public domain.a Once computed, these correlations
were used to ascertain those behaviors and characters
that were most closely correlated with tail chasing.
Nine such characters were found to have estimates of
correlations with tail chasing, and with each other, to
warrant further investigation. However, 7 behavioral
variables (fly-snapping, shadow and light chasing, fly-
snapping and shadow chasing combined, flank suck-
ing, owner aggression 1 interaction, owner aggression
2 interaction, and deafness) were found to have poorly
estimated correlation coefficients (ie, SEs well above
1.0) and were excluded from further analysis.
The remaining 10 variables formed the basis of a
series of log-linear analyses. All possible sets of 8 vari-
ables, where tail chasing was kept in each set (this be-
ing the variable of principle interest), were evaluated.
This was done to balance the interest in estimating un-
known effects against the preponderance of empty cells
given the limited number of dogs observed across the
many subclasses. The initial analyses fit all 8 variables,
including models for 2- and 3-way interactions. In each
setting, nonsignificant variables were removed and a
suitable submodel was chosen through comparisons
of the Akaike Information Criterion and the residual
deviance. In repeating this process over the 9 subsets
of variables, a subset of variables and their interactions
were arrived at, which were consistently found to be
associated with each other. All computations were per-
formed with the general linear model function of the
R programing language with the dependent variable of
counts and a Poisson model with and without consid-
eration of overdispersion.a
Data were collected on 333 Bull Terriers, 145 dogs
with tail-chasing behavior, and 188 unaffected dogs;
however, not all dogs had information recorded for
each descriptive trait. Because some owners did not
answer certain questions, the total number of dogs for
every variable varied.
Sex and neuter status—A total of 169 female and
164 male Bull Terriers were included in the analysis.
Reproductive status was not reported for 6 dogs; re-
productive status was known for 144 dogs with tail-
JAVMA, Vol 238, No. 7, April 1, 2011 Scientific Reports 885
chasing behavior and 183 unaffected dogs. Thirty-one
percent (45/144) of dogs with tail-chasing behavior
were neutered males, and 18% (33/183) of unaffected
dogs were neutered males. Thirteen percent (19/144) of
dogs with tail-chasing behavior were sexually intact fe-
males, and 23% (42/183) of unaffected dogs were sexu-
ally intact females. Thirty-one percent (44/144) of dogs
with tail-chasing behavior were spayed females, and
34% (62/183) of unaffected dogs were spayed females.
Twenty-five percent (36/144) of dogs with tail-chasing
behavior were sexually intact males, and 25% (46/183)
of unaffected dogs were sexually intact males.
Age of onset—Age of onset for tail chasing was
known or confidently estimated for 61% (89/145) of
dogs with tail-chasing behavior. The median age of
onset was 6 months. The range of age of onset was 2
months to 6 years of age.
Frequency and duration of bouts—Frequency
(daily tail chasing or less than daily tail chasing) was
recorded for 109 of the 145 dogs with tail-chasing be-
havior. Of these 109 dogs, 74% (81/109) chased their
tail daily while 26% (28/109) chased their tail less than
daily. Information on the duration (< 2 minutes, 2 to 30
minutes, > 30 minutes) of tail chasing was available for
67% (97/145) of the dogs with tail-chasing behavior.
The average duration of a tail-chasing bout was > 30
minutes for 28% (27/97) of the dogs. Average tail-chas-
ing bouts ranged from 2 to 30 minutes for 29% (28/97)
of the dogs. Average tail chasing bouts that lasted < 2
minutes were reported for 43% (42/97) of the dogs. For
94 dogs with tail-chasing behavior, both frequency and
duration data were available for cross tabulation. Of the
74 dogs that chased their tails daily for which duration
data were also available, 70% (52/74) did so for 2 to
30 minutes or > 30 minutes. By comparison, of the 20
dogs that did not chase their tails daily for which dura-
tion data were also available, only 10% (2/20) did so for
2 to 30 minutes or > 30 minutes (χ² = 23.8; P < 0.001).
Ability to interrupt—Owners of 99 dogs com-
pleted the question regarding the ease with which
they could interrupt their dog’s tail-chasing behavior.
Eighty-seven (88%) owners reported that they could
interrupt their dog from tail chasing. However, 48%
(42/87) of these owners reported that the dog would
immediately or within minutes resume tail chasing,
indicating that the interruption was only temporary.
Thirty-four percent (30/87) of owners indicated that
the dog would either not resume or resume tail chasing
at a later time, suggesting that these dogs were more
easily interrupted. Seventeen percent (15/87) of own-
ers reported that whether the dog resumed tail chasing
following an interruption depended on the situation.
If the dog was bored or stressed at the time, it would
likely resume immediately to within a few minutes. If
the dog’s attention could be redirected onto another ac-
tivity, the tail chasing could be successfully interrupted.
Ten percent (10/99) of owners could not interrupt their
dog’s tail chasing, and 2 owners (2%) did not attempt to
interrupt the behavior.
Triggers—As part of the survey, owners were
asked an open-ended question regarding what condi-
tions triggered the initial onset and continued elicita-
tion of their dog’s tail-chasing behavior. A total of 129
owners responded, but many owners listed > 1 trigger
for tail chasing, resulting in 239 reported triggers. Trig-
gers were grouped into 9 general categories. Thirty-one
percent (73/239) of triggers for tail chasing involved
situations that increased the dog’s level of arousal or
frustration. Examples included owner departures and
returns, visitors, food, presence of other dogs, aggres-
sive interactions with other dogs, exposure to moving
cars and bicycles, being released from a crate, going
outside, the owner cooking, or general excitement.
New, unpredictable or restrictive environments were
submitted as triggers for 18% (43/239) of dogs. This
category included crate confinement, new locations,
closed areas, room corners, and return to indoors. Lack
of mental or physical stimulation and insufficient inter-
action with the owner or conspecific was listed as a trig-
ger for 15% (35/239) of dogs. Sensitivity to sound was
also cited as a trigger for tail chasing for 10% (25/239)
of dogs. Specific sounds reported included loud noises,
rain on the roof and windows, running water, vacuum,
hair dryer, lawn mower, microwave bells, and other
household beeping-type alarms. Physical conditions as-
sociated with the onset and continued elicitation of tail
chasing were cited for 8% (20/239) of dogs and included
first or second estrus cycle, diarrhea, defecation, flatu-
lence, hunger, fatigue, allergies, and tail injury. Ten per-
cent (23/239) of owners reported no discernible trigger
associated with tail chasing and viewed the behavior as
spontaneous. Six percent (14/239) of owners reported
that their dog chased their tail at certain times of the
day or in response to other situations. A change in the
dog’s social group was associated with tail chasing in 2%
(4/239) of dogs. The sight of certain objects (eg, broom
or bag) triggered tail chasing in 1% (2/239) of dogs.
The development of tail-chasing behavior differed
among individuals, varying from a gradual to a sudden
onset. For some dogs, the onset of tail-chasing behavior
occurred suddenly with no apparent trigger, whereas
for other dogs, the onset coincided with exposure to
identifiable psychological, physiologic, or environmen-
tal triggers that were interpreted as increasing anxiety
or arousal levels.
Interference with dog’s quality of life and owner’s
relationship with dog—Fifty-one owners responded to
the question of how tail chasing interfered with their
dog’s normal activities. Twenty-seven percent (14/51)
of owners responded that the behavior occurred with
such high frequency and duration that it was nega-
tively affecting the dog’s ability to function to the point
of incapacitating every aspect of its life. Eighteen per-
cent (9/51) of owners reported definite interference but
that the behavior was still manageable. Sixteen percent
(8/51) reported that the interference was slight (5/51)
to mild to moderate (3/51). Thirty-nine percent (20/51)
reported that the dog’s tail-chasing behavior posed no
Fifty-two dog owners responded to the question
of how much the dog’s tail-chasing behavior interfered
with the relationship with their dog. Twenty-five percent
(13/52) of owners reported that their dog’s tail-chasing
behavior posed an incapacitating interference in the rela-
886 Scientific Reports JAVMA, Vol 238, No. 7, April 1, 2011
tionship with their dog. Another 25% (13/52) of owners
reported that the tail-chasing behavior posed a definite
but manageable interference. Mild to moderate interfer-
ence was reported by 8% (4/52) of owners. Twelve percent
(6/52) of owners found that their dog’s tail-chasing behav-
ior caused a slight interference in the relationship with
their dog, whereas 31% (16/52) reported no interference.
Injuries—Dog owners were not specifically asked
to report injuries until later in the study. Fifteen dogs in-
curred tail injuries as a direct result of biting the tail dur-
ing tail-chasing bouts, 7 of which necessitated amputation
because of the severity of the injuries. Six dogs sustained
injuries to the head and tarsi in the form of abrasions and
cuts from banging into walls and furniture while tail chas-
ing. Two owners reported that their dog’s digital pads and
nails were severely worn because of excessive tail chasing.
Eight dogs that did not respond to treatment were euthan-
atized because of excessive tail chasing. Another 8 dogs
were euthanatized because of tail chasing in conjunction
with owner-directed aggression.
Degrees of expression—On the basis of clinical
impression data from owner reports regarding frequen-
cy, duration, interruptability, and degree of disruption
to the dogs’ normal functioning and the owners’ rela-
tionship with the dogs, 2 subsets of tail-chasing behav-
ior were identified that differed in degree of expression
for the Bull Terrier population of this study: clinical and
subclinical tail-chasing behavior.
Based on differences in frequency of expression only,
dogs with clinical tail-chasing behavior (81/109) were
those dogs that underwent multiple tail-chasing bouts
on a daily basis. They often appear dissociated from the
environment and unresponsive to owner commands.
These dogs were not easily interrupted from tail chasing,
and many had signs of anxiety or aggression if restrained.
If the owner was able to interrupt the dog from tail chas-
ing, usually by restraint or redirection onto a preferred
toy or object, the dog typically resumes immediately
upon release or removal of the object. On the basis of
owner reports, the duration of individual tail-chasing
bouts for dogs with clinical tail-chasing behavior gen-
erally ranged from 60 seconds to > 2 hours. Dogs with
clinical tail-chasing behavior often chased their tail daily,
usually to the exclusion of other normal activities, with
tail-chasing behavior occupying an owner-estimated
30% to 80% of the dog’s daily time budget. The behavior
was disruptive for both the dog and owner and in many
instances was viewed by the owner as incapacitating or
definitely interfering with the dog’s normal functioning
(23/51 [45%]) and relationship with the owner (26/52
[50%]). Owners reported that the dog often chased its
tail rather than interact with their human companions or
other dogs and commented that their dog was no longer
a good companion. These dogs were not reliably respon-
sive to training commands and could not be exercised,
as they chased their tail rather than walking on leash or
chasing a ball. A few dogs were reported to continue to
chase their tail while they urinated and defecated. Some
dogs with clinical tail-chasing behavior mutilated their
tail, sustained tail fractures while tail chasing, had weight
loss (either because they chased their tail rather than eat
or the excessive physical activity resulted in weight loss),
had signs of exhaustion, and had abraded foot pads, all
indicators of the severity of the behavior problem.
By definition, dogs with subclinical tail-chasing be-
havior (28/109) had an apparently milder form of tail
chasing that occurred typically 1 or 2 times/wk or 1 or
2 times/mo, usually in response to specific, predictable
stimuli. The episodes were comparatively short in dura-
tion, usually < 3 minutes, and were easily interrupted
by owners via distraction techniques. These dogs did
not appear dissociated from their environment, re-
sponded to owner commands while tail chasing, and
did not immediately resume tail chasing once they had
been interrupted. Their tail-chasing behavior was not
reported to interfere with the dog’s normal functioning
or its relationship with the owner. However, some dogs
with subclinical tail-chasing behavior later developed
clinical tail-chasing behavior in response to changes in
their environment or physiologic condition.
Fear responses and phobias—A total of 60 Bull Terri-
ers, both dogs with tail-chasing behavior (n = 36) and unaf-
fected dogs (24), were described by owners as having pho-
bias of common objects or situations in their environment.
Some owners reported > 1 trigger for their dog’s fearful be-
havior. Phobias were divided into 3 categories: natural envi-
ronment, social, and situational. Natural environment pho-
bias included the following: vacuums (17/60); loud noises
(8/60) including vehicles, mechanical and machinery noise,
and a noise-making doll; water (9/60) including hose water,
bath water, and rain; stairs (2/60); heights (1/60); thunder-
storms (1/60); slippery floors (5/60); mopping, sweeping,
and raking (9/60); reflective surfaces (3/60); novel house-
hold objects in environment (5/60); common household
objects out of place (5/60); moving or stationary automo-
biles (2/60); fear of own shadow (1/60); fear of outdoors
in daytime (1/60); steel doors (2/60); and doorways (1/60).
Four dogs had social phobias in the presence of people
dressed in white (1/60), strangers (1/60), people speaking
loudly (1/60), and any human contact (1/60). Ten dogs
had situational phobias involving the veterinarian’s office
(3/60), grooming shop (1/60), pet store (1/60), show ring
(1/60), elevators (1/60), crates (1/60), walks (1/60), and be-
ing away from home (1/60).
Owner-directed aggression—From the total of
333 dogs, 14 dogs with tail-chasing behavior expressed
owner-directed aggression in 5 types of interactions
with owners. Five unaffected dogs expressed owner-
directed aggression in 5 situations.
Episodic aggression—Twenty-two dogs had epi-
sodic aggression. Sixteen dogs with episodic aggression
were dogs with tail-chasing behavior, and 6 were unaf-
fected dogs. Ninety-five percent (20/21) of dogs with
episodic aggression (not observed for 1 dog with epi-
sodic aggression) went directly from a sleep state to an
attack state. All episodes were < 60 seconds in dura-
tion as described by owners. Forty-one percent (9/22)
of owners also marked situations or interactions on the
owner-directed aggression checklist that resulted in ag-
gression. In all 9 instances, aggression was reported to
be triggered by only 1 or 2 specific interactions.
Association of tail chasing with other variables—For
determination of what physical and behavioral characteristics
JAVMA, Vol 238, No. 7, April 1, 2011 Scientific Reports 887
were correlated with tail chasing, 10 variables were evaluated
(Table 1). Correlations (and their associated SEs) among the
10 variables were considered in the analysis. Increased risk
for developing tail chasing was not associated with coat color;
dogs with white or other color coats appeared at equal risk.
A history of tonic clonic seizures, deafness, or skin allergies
also was not associated with increased risk of developing tail
chasing, and neither was a history of shadow chasing, fly-
snapping, flank sucking, or noise sensitivity.
However, on the basis of polychoric correlations,
several behaviors were aggregated (Table 1). Tail chasing
occurred frequently with owner-directed aggression and
episodic aggression (polychoric correlations of 0.377 and
0.374, respectively). Similarly, the behavior of noise sensi-
tivity occurred frequently with episodic aggression (poly-
choric correlation of 0.644).
A log-linear model including terms for tail chasing,
episodic aggression, trance-like behavior, phobia, sex,
and owner-directed aggression ( 5 types of interactions),
along with all possible 2-way interactions, was developed
(Table 2); this model captured those variables that provid-
ed the best fit to the observed counts. Not presented is the
model with all possible 3-way interactions, none of which
proved to be significantly different from zero, a result that
was repeated across all models and submodels evaluated.
Other submodels not presented included selected 3-way
interactions; however, at no time were any of these terms
significantly different from zero.
Episodic aggression and trance-like behavior, along
with sex, had significant interactions with tail chasing
(Table 2). There was an 8% increase in tail-chasing males
(exp 0.078 = 1.081). Positive parameter estimate for the
Poisson model demonstrates that the observed frequency
of male dogs that chase their tail, as well as male dogs that
have had either episodic aggression or trance-like behav-
ior, is more common than can be explained by a model
of independent occurrence of these characteristics (ie, pa-
rameter estimates of 0.078, 0.620, and 0.883 vs –1.189,
–2.871, and –3.493, respectively). In fact, the Akaike in-
formation criterion for the model with only main effects
of tail chasing, episodic aggression, trance-like behavior,
phobia, sex, and owner-directed aggression was 200.82,
whereas the Akaike information criterion for the log-lin-
ear model was 184.84. Accordingly, the log-linear model
provided a better explanation for the observed counts of
these traits than that of an independent (ie, no interac-
tion) model. Tail-chasing behavior was more commonly
found with episodic aggression and trance-like behavior
than what would be expected given the probability of
these 3 behaviors taken individually. However, the failure
of a 3-way interaction to be significant, or for the episodic
aggression and trance-like behavior interaction to be sig-
nificant (P = 0.127), suggested that tail chasing was segre-
gated with each of these aberrant behaviors, but that epi-
sodic aggression and trance-like behavior were unrelated.
To our knowledge, the study reported here represents
the largest study of tail chasing in Bull Terriers to date. Tail
chasing has been documented as a form of canine com-
pulsive disorder.2,7–9 Some of the previous assertions about
Variables Sex Coat Tailch Tr Phobia Noise Ownagg EA Seizures Skin
Sex 1.000 0.085 0.193 –0.200 –0.032 –0.045 0.171 –0.110 –0.182 –0.003
Coat 0.008 1.000 0.052 –0.005 0.135 –0.016 0.267 –0.006 –0.359 0.353
Tailch 0.007 0.008 1.000 0.107 0.296 0.172 0.377 0.374 0.273 0.156
Tr 0.008 0.009 0.009 1.000 0.204 0.350 0.158 0.155 0.453 0.167
Phobias 0.010 0.010 0.009 0.011 1.000 0.465 0.215 0.352 0.070 0.147
Noise 0.010 0.010 0.009 0.009 0.008 1.000 0.339 0.644 0.465 0.029
Ownagg 0.019 0.018 0.016 0.020 0.022 0.018 1.000 0.265 0.151 –0.003
EA 0.017 0.019 0.015 0.019 0.017 0.009 0.032 1.000 0.542 0.333
Seizures 0.032 0.037 0.030 0.024 0.042 0.025 0.063 0.029 1.000 0.277
Skin 0.008 0.007 0.007 0.009 0.010 0.010 0.020 0.015 0.030 1.000
Sex was scored as 1 for male and 0 for female; coat color was scored as 1 for white and 0 for color. All behaviors were scored as a 1 for yes
and 0 for no.
EA = Episodic aggression. Noise = Noise sensitivity. Ownagg = Owner-directed aggression. Seizures = Seizure events. Skin = Skin allergies.
Tailch = Tail chasing. Tr = Trance-like behavior.
Table 1—Polychoric correlation values (above the diagonal [bolded 1.000 values]) and their SEs (below the diagonal) among behavioral
and explanatory characteristics in 333 Bull Terriers (145 dogs with tail-chasing behavior and 188 unaffected dogs).
Parameter Estimate SE t value* Pr . |t|†
Intercept 1.908 0.278 6.854 0.000
Tailch 0.035 0.005 7.512 0.000
Ownagg –0.005 0.317 –0.016 0.987
EA –2.871 0.545 –5.271 0.000
Tr –3.493 0.720 –4.850 0.000
Sex –1.189 0.441 –2.698 0.010
Phobia –0.104 0.358 –0.292 0.772
Tailch X Ownagg 0.009 0.008 1.141 0.260
Tailch X EA 0.604 0.219 2.752 0.009
Tailch X Tr 1.057 0.303 3.487 0.001
Tailch X Sex 0.078 0.021 3.730 0.001
Tailch X Phobia 0.005 0.007 0.735 0.466
Ownagg X EA 0.334 0.564 0.593 0.557
Ownagg X Tr –0.226 0.535 –0.422 0.675
Ownagg X Sex 0.282 0.302 0.935 0.355
Ownagg X Phobia –0.220 0.263 –0.835 0.408
EA X Tr 1.209 0.778 1.555 0.127
EA X Sex 0.620 0.556 1.116 0.271
EA X Phobia –0.001 0.529 –0.001 0.999
Tr X Sex 0.883 0.505 1.749 0.088
Tr X Phobia 0.101 0.438 0.231 0.818
Sex X Phobia 0.257 0.302 0.851 0.399
*t value = t statistic for test. †Pr . |t| = Significance level for
test; values , 0.05 are considered significant.
See Table 1 for remainder of key.
Table 2—Parameter estimates and their SEs for the log-linear
model without consideration of overdispersion including counts
of tail chasing, episodic aggression, trance-like behavior, sex,
owner-directed aggression, and phobia, and all possible 2-way
interactions for 145 Bull Terriers with tail-chasing behavior.
888 Scientific Reports JAVMA, Vol 238, No. 7, April 1, 2011
this purported canine compulsive disorder were confirmed
and more closely detailed in the present study, while new
findings, in particular, increased male susceptibility and
associations of tail chasing with episodic aggression and
trance-like (staring) behaviors, were made. These conclu-
sions were based on significant interaction terms for these
behaviors with tail chasing. Interestingly, there were initial
models for this study in which owner-directed aggression
and phobias were found to have a significant interac-
tion with tail chasing. However, these initial exploratory
models did not include terms for episodic aggression or
trance-like behavior. Accordingly, overall interpretation of
the final model developed in this study suggests that al-
though owner-directed aggression and phobias had some
impact on tail chasing, trance-like behavior and episodic
aggression associate more strongly with tail chasing. This
general observation was also supported in the polychoric
correlation values (Table 1).
Our clinical perception was that many Bull Terriers
with tail-chasing behavior had mild owner-directed ag-
gression (as distinct from violent episodic aggression),
although statistical analysis indicated only a loose as-
sociation. A clinical explanation for the association of
tail chasing with owner-directed aggression may be that
increased anxiety, frustration, or conflict associated
with the performance of tail chasing or the owners’ at-
tempts to interrupt tail chasing lower the threshold for
the dogs’ aggressive response toward their owners.
The weak association between compulsive tail
chasing and phobic conditions is explicable if tail-
chasing compulsion, like human obsessive-compulsive
disorder, is regarded as an anxiety disorder.13 According
to the diagnostic manual of the American Psychiatric
Association,13 various anxiety-type disorders, including
specific phobia, social phobia, and panic disorder, are
comorbid with obsessive-compulsive disorder. Find-
ings of the study reported here suggest that a similar
association of tail-chasing compulsion and anxiety-type
disorders exists for Bull Terriers and support the bio-
logical homology concept of canine and human com-
pulsive behavior.
Although tail chasing in dogs is commonly de-
scribed as a compulsive disorder or partial seizure dis-
order,2,4,7–9 findings of the present study lead to another
possibility. Males had a slight (8%) but significantly
greater risk for developing tail chasing than females
(Table 2). Furthermore, tail chasing in Bull Terriers is
closely associated with episodic aggression and trance-
like behavior. In terms of the cluster of clinical signs
and manifestations of tail chasing, it is speculated that
this syndrome in Bull Terriers may have features in com-
mon with autism in humans. Autism is also more com-
mon in males, is associated with explosive aggression,
trance-like staring, and involves repetitive movements
and self-injurious behavior.14–16 In addition, autism is
characterized by autonomy, impaired social interac-
tions, and obsession with objects.16–18 Many owners of
Bull Terriers with tail-chasing behavior describe their
dogs as asocial, somewhat withdrawn, and abnormally
preoccupied with objects, such as balls or sticks. In-
deed, many owners use objects to redirect their dog
from tail chasing, and the dog responds to the distrac-
tion with similar intensity.
A final possible explanation for the relationship be-
tween tail chasing, trance-like behavior, and episodic
aggression is that all stem from underlying complex
partial seizures. Bull Terriers with tail-chasing behav-
ior have been shown to have epileptiform activity on
electroencephalographic recordings.4 Furthermore, vi-
olent episodic aggression in dogs has previously been
described as a seizure-related problem,19,20 and trance-
like behavior may represent a form of partial seizure in
which consciousness is altered but not lost. It is note-
worthy that epileptic seizures are reported in 4% to 32%
of humans with autism.21,22
The present study provides detailed phenotypic
and developmental information about tail chasing in
dogs and illustrates some intriguing parallels with hu-
man obsessive-compulsive disorder and possibly au-
tism. Compulsions are typically time-consuming in
clinical tail chasing and obsessive-compulsive disorder,
and the behavior seems to be performed in response to
and in order to alleviate stress. If a dog with tail-chasing
behavior or a human with obsessive-compulsive disor-
der is physically prevented from engaging in a compul-
sion, the result is mounting anxiety or tension.13 Re-
peating actions in an excessive or unreasonable manner
is a way that obsessive-compulsive disorder presents in
humans and is the primary manifestation of tail chasing
in dogs.7 In addition, the onset of tail chasing typically
occurs in young adulthood shortly before or just after
puberty. Early-life onset is also a feature of both obses-
sive-compulsive disorder and autism in humans.23,24
As with obsessive-compulsive disorder, a familial
pattern of expression of tail chasing has been described.7
Obsessive-compulsive disorder and tail chasing affect
so-called occupational or normal daily functioning and,
as shown in this study, have a detrimental effect on so-
cial activities and relationships with others. Both disor-
ders can be disruptive to overall functioning and may
lead to self-injury. Furthermore, there is comorbidity
between tail chasing and various phobias, as occurs in
obsessive-compulsive disorder. That said, over 10% of
autistic children have noise phobias and clinically di-
agnosable problems of an anxiety-related disorder, and
in addition, autism is familial in expression, with an
increased risk among siblings.24 Dogs with tail-chasing
behavior seem to be of an anxious disposition and have
been shown to respond to the same types of medica-
tions.2,25 Although there are many parallels between
canine compulsive tail chasing and human obsessive-
compulsive disorder, if tail chasing in Bull Terriers is
more closely related to autism, a new channel of trans-
lational research could be pursued relative to this com-
mon and extremely debilitating condition.
a. polycor: Polychoric and polyserial correlations, R Package, ver-
sion 07-7, R Foundation for Statistical Computing, Vienna, Aus-
tria. Available at: Accessed Jul 7, 2009.
1. Blackshaw JK, Sutton RH, Boyhan MA. Tail chasing or circling
behavior in dogs. Canine Pract 1994;19(3):7–11.
2. Moon-Fanelli AA, Dodman NH. Description and development
of compulsive tail chasing in terriers and response to clomip-
ramine treatment. J Am Vet Med Assoc 1998;212:1252–1257.
JAVMA, Vol 238, No. 7, April 1, 2011 Scientific Reports 889
3. Brown SA, Crowell-Davis S, Malcolm T, et al. Naloxone-
responsive compulsive tail chasing in a dog. J Am Vet Med Assoc
4. Dodman NH, Knowles KE, Shuster L, et al. Behavioral changes
associated with suspected complex partial seizures in Bull Terri-
ers. J Am Vet Med Assoc 1996;208:688–691.
5. Dodman NH, Bronson R, Gliatto J. Tail chasing in a Bull Terrier.
J Am Vet Med Assoc 1993;202:758–760.
6. Uchida Y, Moon-Fanelli AA, Dodman NH, et al. Serum concen-
trations of zinc and copper in Bull Terriers with lethal acroderma-
titis and tail-chasing behavior. Am J Vet Res 1997;58:808–810.
7. Dodman NH, Moon-Fanelli AA, Mertens PA. Veterinary models of
OCD. In: Hollander E, Stein DJ, eds. Obsessive-compulsive disorders: di-
agnosis, etiology, treatment. New York: Marcel Dekker Inc, 1997;99–143.
8. Luescher A. Diagnosis and management of compulsive disorders
in dogs and cats. Clin Tech Small Anim Pract 2004;19:233–239.
9. Overall KL, Dunham AE. Clinical features and outcome in dogs
and cats with obsessive-compulsive disorder: 126 cases (1989–
2000). J Am Vet Med Assoc 2002;221:1445–1452.
10. Dodman NH, Smith A, Holmes D. Comparison of the efficacy of re-
mote consultations and personal consultations for the treatment of dogs
which are aggressive towards their owners. Vet Rec 2005;156:168–170.
11. McCullagh P, Nelder JA. Generalized linear models. 2nd ed. Lon-
don: Chapman & Hall, 1989.
12. Olsson U. Maximum likelihood estimation of the polychoric
correlation coefficient. Psychometrika 1979;44:443–460.
13. American Psychiatric Association. Diagnostic and statistical
manual of mental disorders. 4th ed. Washington, DC: American
Psychiatric Association, 1995.
14. Bodfish JW, Symons FJ, Parker DE, et al. Varieties of repetitive
behavior in autism: comparisons to mental retardation. J Autism
Dev Disord 2000;30:237–243.
15. Parikh MS, Kolevzon A, Hollander E. Psychopharmacology of
aggression in children and adolescents with autism: a critical re-
view of efficacy and tolerability. J Child Adolesc Psychopharmacol
16. Stone JL, Merriman B, Cantor RM, et al. Evidence for sex-specific risk
alleles in autism spectrum disorder. Am J Hum Genet 2004;75:1117–
17. Williams E, Costall A, Reddy V. Children with autism experi-
ence problems with both objects and people. J Autism Dev Dis-
ord 1999;29:367–378.
18. Kim JA, Szatmari P, Bryson SE et al. The prevalence of anxiety
and mood problems among children with autism and Asperger
syndrome. Autism 2000;4:117–132.
19. Dodman NH, Miczek KA, Knowles K, et al. Phenobarbital-re-
sponsive episodic dyscontrol (rage) in dogs. J Am Vet Med Assoc
20. de Lahunta A. Nonolfactory rhinencephalon: limbic system. In:
Veterinary neuroanatomy and clinical neurology. 2nd ed. Phila-
delphia: WB Saunders Co, 1983;318.
21. Gabis L, Pomeroy J, Andriola MR. Autism and epilepsy: cause,
consequence, comorbidity or coincidence? Epilepsy Behav 2005;
22. Rossi PG, Parmeggiani A, Bach V, et al. EEG features and epi-
lepsy in patients with autism. Brain Dev 1995;17:169–174.
23. Short AB, Schopler E. Factors relating to age of onset in autism.
J Autism Dev Disord 1988;18:207–216.
24. Chabane N, Delorme R, Millet B, et al. Early-onset obsessive-
compulsive disorder: a subgroup with a specific clinical and fa-
milial pattern. J Child Psychol Psychiatry 2005;46:881–887.
25. Hewson CJ, Luescher UA, Parent JM, et al. Efficacy of clomip-
ramine in the treatment of canine compulsive disorder. J Am Vet
Med Assoc 1998;213:1760–1766.
... more persistent 10 . Ultimately, severe repetitive behaviour may considerably worsen the quality of life 14 and the dog-owner relationship 16 . ...
... Health issues and pain can be underlying causes as well 2,14,18 . Furthermore, comorbidity between repetitive behaviours and other behavioural problems have been reported in dogs and other animals 7,13,14,16,18 . Additionally, heritable contributions have been demonstrated by the observed breed-specificity of repetitive behaviours, as well as recent gene discoveries 14,[19][20][21][22] . ...
... However, the equivalence of canine and human compulsions has been challenged 40 . Different forms of OCD and canine compulsive disorder probably involve some different factors, but it can be suggested that different compulsions also overlap and share biological etiology and common genetic factors 13,14,16 . ...
Full-text available
Repetitive behaviour ranges from variants of normal repetitive behaviours to abnormal repetitive behaviours. The domestic dog spontaneously performs different repetitive behaviours, which can be severe and impair the quality of life and the dog-owner relationship. We collected comprehensive behavioural questionnaire data from almost 4500 Finnish pet dogs and studied the effect of several demographic, environmental, and behavioural factors on canine repetitive behaviour with logistic regression. We replicated findings from previous studies by revealing comorbidity between repetitive behaviour and behavioural factors aggressiveness, hyperactivity/impulsivity, and inattention. We also found a novel association between repetitive behaviour and the owner’s dog experience. In addition, we showed that repetitive behaviour is more common in dogs that live without conspecifics, dogs that were given a low amount of exercise, dogs that lived in larger families, young dogs and elderly dogs, and neutered dogs. Finally, we identified breed differences in repetitive behaviour, suggesting that some breeds are more vulnerable to repetitive behaviour and indicate a genetic susceptibility. As abnormal repetitive behaviour can considerably worsen the well-being of dogs and impair the dog-owner relationship, a better understanding of the environmental, lifestyle, and molecular factors affecting canine repetitive behaviour can benefit both dogs and humans.
... The frequency and intensity of these diverse behaviours are variable, but can be severe. For example, in a survey of tail-chasing bull terriers (Moon-Fanelli et al., 2011), 27 % of owners reported that the behaviour occurred with such high frequency and duration that it was incapacitating every aspect of the dog's life. It can also be a life-threatening disorder; Escriou et al. (2012) report that 14 out of 44 dogs in their sample were euthanized due to the severity of the condition. ...
... Other studies (Stein et al., 1998;Wynchank and Berk, 1998) continued to support the proposal of ALD as an analogue of OCD based on the repetitiveness of the licking behaviour and on its pharmacological response. Subsequently a wider range of ARBs including flank-sucking, licking, fly-snapping, tail-chasing and shadow-chasing were likened to OCD in humans (Overall, 2000;Dodman et al., 2010;Escriou et al., 2012;Ogata et al., 2013;Dodman et al., 2016;Noh et al., 2017) There have even been suggestions from both the psychiatry literature (Stein et al., 1998;Wynchank and Berk, 1998;Dodman and Schuster, 2005;Vermeire et al., 2012) and the veterinary science literature (Moon-Fanelli et al., 2011;Dodman et al., 2016) that ARB in dogs is so similar to OCD that it can serve as a model for OCD with implications for interventions with humans. Despite some reservations regarding the extent to which this is the case (Mills and Luescher, 2006;Tynes and Sinn, 2014), the idea of a canine compulsive disorder which is analogous to OCD persists in contemporary research (e.g. ...
... Whilst there are published accounts of functional analyses being applied to other behaviour problems in dogs (Dorey et al., 2011;Winslow et al., 2018;Pfaller-Sadovsky et al., 2019), there are few reports of such investigations of ARBs. Some studies (Moon-Fanelli et al., 2007;Pereira et al., 2010;Moon-Fanelli et al., 2011;Tiira et al., 2012) have used surveys to identify eliciting triggers, but this review could find only one published functional analysis of ARBs (Hall et al., 2015). Turning first to the surveys, they report a wide variety of antecedents. ...
In the literature on companion animal behaviour, a diverse range of repetitive behaviours in dogs have been referred to as symptoms of an underlying canine compulsive disorder analogous to obsessive-compulsive disorder in humans. It is claimed that the two disorders are behaviourally equivalent and have the same neurophysiology and response to pharmacological treatment. These claims are largely derived from the bio-medical perspective and have neglected the cognitive-behavioural model of obsessive-compulsive disorder in humans which accounts for the development and maintenance of the disorder in terms of learning theory and cognitive processing. In order to develop a fuller understanding of canine repetitive behaviours it is important to consider all perspectives and avoid limiting therapeutic approaches. This paper reviews the claims of equivalence from the cognitive-behavioural perspective and also reviews the evidence for any pathophysiological similarities between the two disorders. The review finds that claims of behavioural equivalence are based on the superficial characteristic of repetitiveness whilst neglecting the function of the behaviour; there are no reliable or consistent indications of the same neuroanatomy or physiology being specifically associated with the two disorders and whilst both appear to show a partial response to the same pharmacotherapy, it is not clear that this response is specific to both disorders. The review concludes that although there is little research data with which to make a comprehensive comparison, the available studies suggest that abnormal repetitive behaviours in dogs are unlikely to be the equivalent of human obsessive-compulsive disorder. There is considerable scope for further investigation of the cognitive, behavioural and emotional components of canine repetitive behaviours using current and emerging methodologies.
... Inicia-se como resposta a um conflito ou a uma frustração e, após um tempo, sai do seu contexto original (Seksel e Lindeman, 2001 Tiira et al. (2012), a idade média de início desse distúrbio em Bull Terriers é em torno de três a seis meses de vida, mas pode variar de dois meses a seis anos de idade. Machos possuem 8% mais chances de desenvolverem a PCC do que fêmeas, e animais castrados são menos acometidos por PCC quando comparados com animais inteiros (Moon-Fanelli et al., 2011;Tiira et al., 2012). Além disso, Tiira et al. (2012) verificaram que os cães que recebem suplementação dietética, como vitaminas e minerais (especialmente vitaminas C e B6), apresentam menos PCC que animais não suplementados. ...
... A elevada associação entre os transtornos obsessivos compulsivos e as raças é um forte indicativo de que essas alterações de comportamento podem estar correlacionadas a uma mutação genética (Overall e Dunham, 2002;Dodman et al., 2010;Tiira et al., 2012;Mosallanejad et al., 2016), entretanto a origem desse distúrbio ainda é pouco compreendida (Tynes e Sinn, 2014). Dentro das manifestações clínicas, a PCC é mais comumente observada em cães das raças Bull Terrier e Pastor Alemão, sendo caracterizada por andar em círculos lentos ou rápidos, com a atenção do animal direcionada à cauda, ou movimentos giratórios em círculos rápidos e estreitos, sem foco aparente na cauda, podendo essas duas formas serem expressas em um mesmo cão, de maneira intercalada (Moon-Fanelli et al., 2011;Tynes e Sinn, 2014 Os bloqueadores da recaptação de serotonina são os principais fármacos utilizados para tratamento de TOC em cães (Tynes e Sinn, 2014), sendo representados pelos antidepressivos tricíclicos, que bloqueiam a recaptação neuronal tanto de serotonina quanto de norepinefrina. Entretanto, além do uso de medicamentos, é fundamental a mudança no manejo ambiental e a remoção dos estímulos estressantes (Seksel e Lindeman, 2001). ...
... Suspeita-se que cães que apresentam TOC têm disfunção neuroquímica primária ou neurogênica (Overall e Dunham, 2002), tendo características semelhantes com autismo descrito em humanos (Moon-Fanelli et al., 2011). Os principais neurotransmissores ligados ao estresse são a dopamina e a serotonina, sendo este último o mais importante na patogenia dos distúrbios compulsivos. ...
Full-text available
RESUMO A perseguição compulsiva da cauda consiste em um distúrbio caracterizado por movimentos giratórios em círculos, lentos a rápidos com ou sem foco na cauda. É uma desordem comportamental comumente observada em cães da raça Bull Terrier, sendo mais frequente em machos, com início entre três e seis meses de idade. O diagnóstico é realizado com base no histórico do paciente junto com exames físico, neurológico e laboratoriais. O tratamento pode ser feito por meio do manejo ambiental e da retirada de fatores estressantes aliados a medicamentos antidepressivos. O objetivo deste artigo é relatar o caso de um Bull Terrier que apresentava perseguição compulsiva da cauda e teve evidente melhora clínica 75 dias após início do tratamento com clomipramina. A melhora foi ainda maior após a orquiectomia. A clomipramina consiste em um antidepressivo tricíclico promissor no tratamento de perseguição compulsiva da cauda em cães, devendo-se associar alteração no manejo ambiental e evitar gatilhos que induzam frustração, ansiedade e conflito.
... Neste animal optou-se pela realização da OSH, conforme indicado por Tiira et al. [20], com a finalidade de diminuir os comportamentos compulsivos. Moon-Fanelli et al. [13] fizeram um estudo com cães com comportamentos compulsivos de perseguição de cauda, e observaram maior prevalência em machos do que fêmeas. Ainda neste mesmo trabalho, o autor observou que o efeito da castração foi significativo apenas entre as fêmeas no controle comportamental do DC [13,20]. ...
... Moon-Fanelli et al. [13] fizeram um estudo com cães com comportamentos compulsivos de perseguição de cauda, e observaram maior prevalência em machos do que fêmeas. Ainda neste mesmo trabalho, o autor observou que o efeito da castração foi significativo apenas entre as fêmeas no controle comportamental do DC [13,20]. ...
Full-text available
Background: Compulsive disorders are excessive and repetitive behaviors that jeopardize the quality of life of both animal and tutor. It generally affects dogs between 6 and 36 months of age, and its etiology is associated to stress, anxiety and genetic predisposition. Clinical manifestations are the usual behaviors of the dog, but overly and inappropriately done. Diagnosis is based on a history of repetitive behavior, and on clinical and complementary exams to discard other diseases. The aim of this study is to report a case of compulsive disorder in a female Border Collie dog, including diagnostic and therapeutic approaches.Case: A 5-month-old, female, Border Collie dog was presented to Uberaba’s Veterinary Hospital (HVU) owing to a chasing shadows behavior that started as a playtime activity but intensified to the point of becoming a repetitive and excessive act, followed by self-trauma and excessive barking. Clinical examination showed lesions in nasal planum region. No alterations were observed on neurological examination apart from the chasing of shadows that also happened in the consultation room. Therefore, since there were no other findings on clinical and neurological exams, and since the manifestation occurred as a response to environmental stimuli (presence of shadows), it was established a presumptive diagnosis of compulsive disorder. Treatment with trazodone chlorhydrate was performed, and it was indicated ovariohysterectomy, a follow-up with a professional behaviorist and trainer and environment modifications. After a fortnight, it was observed a discreet improvement of the clinical signs, hence a second anxiolytic, clomipramine, was added to the treatment. Approximately 3 months after the beggining of therapy, there was improvement of the animal’s clinical picture, being calmer and most days ignoring the shadows.Discussion: Compulsive disorders are described as exaggerated and repetitive behaviors that jeopardize the animal’s interaction with its environment and with its tutor. The animal of this report showed repetitive behavior of chasing shadows, with claw abrasion and self-inflicted nasal lesions caused by leaping and biting on the surfaces where the shadows were projecting. Additionally, during the manifestation of the behavior, the animal barked excessively, which compromised the quality of the tutors’ lives. The patient was a Border Collie female dog, though there are no descriptions of this type of behavior in this breed. The starting age of this patient’s manifestations is consistent with previous reports, which observed it more frequently in animals with 6 to 36 months of age. The absence of alterations on clinical and neurological exams that could indicate maladies in other systems, in addition to a detailed anamnesis and assessment of videos of the animal recorded in his domicile, enabled the diagnosis of compulsive disorder. Ovariohysterectomy was done with the purpose of reducing the previously mentioned behavior. Drug therapy in addition to behavior training were efficient to promote significant improvement, although the duration of treatment is a long-term one, as described by other authors. Further studies are necessary for enlightenment of compulsive disorder’s physiopathology in dogs, and to investigate and identify the causes, such as environmental factors and genetic characteristics, that trigger these behaviors.
... As previously hypothesized, dog TC might arise, at least in part, from lack of activities, exercise, or stimulation (34), and increased arousal/frustration and boredom were well-described as one of main CD-triggering factors (7,34,35). To this end, cooperative activities between dog and owners are considered of great importance in the rehabilitation field (36). ...
Full-text available
Compulsive disorder is a debilitating condition affecting both humans and animals, characterized by intrusive thoughts and recurring out-of-place behaviors. Among them, tail chasing might represent one of the most common traits in compulsive dogs. Herein, we reported the case of a 7-year-old intact male German Shepherd mixed-breed dog, presenting with tail chasing behavior. He underwent a first behavioral evaluation 1 year before (at the age of 6), when he injured himself with severe wounds at level of the tail and left thigh. To avoid any specific suffering and increase his physical health, of course, the study was carried out through an interdisciplinary approach, employing a veterinary behaviorist and a rehabilitating dog instructor. Three months after pharmacological treatment with fluoxetine and α-s1 casozepine, associated with a behavioral recovery program, the owner reported an improvement of compulsive events in his dog, in terms of intensity and frequency. Interestingly, over the following 3 months, the dog did not experience any new tail chasing episodes.
... The mapping of anomalous behavior will be a further goal of Dog10K and may be one situation where 'affected' dogs can be included without compromising other goals, as the resulting sequence is useful for mapping not only behavioral anomalies but also all other studies of demography, Mendelian disease and morphology. Obvious breeds for inclusion are those with obsessive compulsive disorders (OCD) [106] including the Bull Terrier, which is well known for its compulsive tail chasing [107,108], and Doberman Pinschers with their blanket-and flank-sucking behavior [109]. Genetic analyses suggest that the CDH2, CTNNA2, ATXN1, and PGCP genes are involved in OCD [110] and have led to the detection of four genes in related pathways in humans [111]. ...
Full-text available
Dogs are the most phenotypically diverse mammalian species, and they possess more known heritable disorders than any other non-human mammal. Efforts to catalog and characterize genetic variation across well-chosen populations of canines are necessary to advance our understanding of their evolutionary history and genetic architecture. To date, no organized effort has been undertaken to sequence the world's canid populations. The Dog10K Consortium ( is an international collaboration of researchers from across the globe who will generate 20× whole genomes from 10 000 canids in 5 years. This effort will capture the genetic diversity that underlies the phenotypic and geographical variability of modern canids worldwide. Breeds, village dogs, niche populations and extended pedigrees are currently being sequenced, and de novo assemblies of multiple canids are being constructed. This unprecedented dataset will address the genetic underpinnings of domestication, breed formation, aging, behavior and morphological variation. More generally, this effort will advance our understanding of human and canine health.
... These findings thus rejected Hypotheses 2 and 3. They also failed to replicate a previous study from our lab (Harper et al., 2015), and findings from other species (with compulsive tail-chasing in bull terriers being associated with increased aggression (Dodman et al., 1996;Moon-Fanelli et al., 2011); polydipsic pigs performing more agonism (Terlouw et al., 1991); and previously socially-deprived monkeys being both more stereotypic and likely to show aggression during nonthreatening encounters with conspecifics (Kempes et al., 2008). Likewise, Hypothesis 4, that depressive-like effects of NE housing (inferred from IBA and helplessness in Forced Swim Tests) cause increased agonism, was also not supported. ...
Compared to female mice raised in large, environmentally enriched (EE) cages, those from “shoebox” non-enriched (NE) cages demonstrate more stereotypic behaviour (SB) and depressive-like effects (i.e. learned helplessness; and inactive-but-awake behaviour [IBA], where a mouse simply stands still). Past research showed that NE females also display more agonistic behaviour (i.e. conflict/aggression) but why this occurs was unknown. We sought to replicate this phenomenon, and to explain it by testing several hypotheses: that NE mice are more agonistic than EE mice because 1) they have higher social interaction rates due to having less space and fewer things to do; 2) NE mice with high levels of SB are behaviourally inflexible and thus socially impaired (and additionally may be at risk of receiving agonism for this same reason); 3) NE mice who display depressive-like effects perceive others as threatening. Via home-cage scan-sampling, we observed behaviours (notably SB, IBA, social interaction rate and agonism) in 165 females (99 NE, 66 EE) of three co-housed strains (C57BL/6 s, BALB/cs, and DBA/2 s; 99 NE) over a 7 month period. EE mice were housed in 60 x 60 cm cages with running wheels, various nesting materials, climbing structures, and chewable items; while NE mice were housed in standard shoebox cages with nesting materials only. At 16 months of age, mice underwent Forced Swim Tests, in which they were placed in individual beakers of water and the duration of floating was measured (versus active swimming), since longer float times suggest higher learned helplessness. We successfully replicated past research: all variables (SB, IBA, social interaction rates, FST float times, and agonism) were significantly higher in NE mice than EE mice (P < 0.0001). Furthermore, NE mice were still more agonistic than EE mice after controlling for their higher social interaction rate (P < 0.0001). Thus, while social activity partially explained the housing effect on agonism, it could not fully explain it, suggesting that there may be intrinsic factors involved. However, we found no relationships between agonism and SB, IBA, and FST float times. Overall, this is the fourth study to show that NE mice are more agonistic than EE mice - further demonstrating the welfare benefits of providing enrichment. This is also the first study to examine potential explanations behind high agonism in NE subjects. We end by suggesting further hypotheses for future test in mice and other species.
In veterinary behavioral medicine and in veterinary neurology, there is an effort to collaborate with different consultants, as seen both in human psychiatry and in human neurology. This cooperation can lead to a complete assessment of any case, to a more holistic collection of information regarding the development of the case, and to a synergetic vision regarding the therapy. In other words, it is essential to understand how behavioral medicine and neurology are linked together to improve diagnosis and therapy process. This review emphasizes the bond between neurology and behavior starting with the neuroanatomic basis of anomalies in veterinary behavioral medicine such as: limbic system, temporal and frontal lobe, pituitary gland, spinal cord, meninges and peripheral nerves. After that, the review deals with some disorders which overlap between neurology and behavioral medicine, and it will conclude by analyzing the differential diagnoses of the neurological diseases and their relationship with behavioral signs.
Experiment Findings
Full-text available
DANGEREOUS DOGS ; AGGRESSIVENESS ; LEGISLATION ; PUBLIC HEALTH ; BEHAVIOR ; DOGBITE ; RISK MANANAGMENT Risk assesment. Identification of danger. Emission X exposition = Probability of Risk. Risk consequences. Behavioural Evaluation. Behavioural Medicine. Dogs. French Law. Law Proposal. Law of 06/01/1999 and Law of 2007 and Law of 2008.
Full-text available
The polychoric correlation is discussed as a generalization of the tetrachoric correlation coefficient to more than two classes. Two estimation methods are discussed: Maximum likelihood estimation, and what may be called two-step maximum likelihood estimation. For the latter method, the thresholds are estimated in the first step. For both methods, asymptotic covariance matrices for estimates are derived, and the methods are illustrated and compared with artificial and real data.
Full-text available
Episodic dyscontrol (rage) was diagnosed from the clinical history, electroencephalographic findings, and response to oral treatment with phenobarbital in 3 dogs. Clinical features included a mood change heralding aggressive incidents, explosive aggression directed at people or objects, and a postaggressive phase characterized by lethargy and lack of responsiveness. Abnormal electroencephalographic findings included spike activity in the temporal recordings. All 3 dogs responded well to anticonvulsant medication with phenobarbital.
This article discusses the presenting signs, diagnosis, and differential diagnosis of compulsive disorder. Problems with the diagnosis and heterogeneity of the condition are discussed. Likely causes, development, and pathophysiology of the condition form the basis for the clinical approach to the treatment of the condition. Treatment includes environmental and management changes, behavioral modification, and drugs.
The objective of this study was to report on the prevalence and correlates of anxiety and mood problems among 9- to 14- year-old children with Asperger syndrome (AS) and high-functioning autism. Children who received a diagnosis of autism (n 40) or AS (n 19) on a diagnostic interview when they were 4 to 6 years of age were administered a battery of cognitive and behavioural measures. Families were contacted roughly 6 years later (at mean age of 12 years) and assessed for evidence of psychiatric problems including mood and anxiety disorders. Compared with a sample of 1751 community children, AS and autistic children demonstrated a greater rate of anxiety and depression problems. These problems had a significant impact on their overall adaptation. There were, however, no differences in the number of anxiety and mood problems between the AS and autistic children within this high-functioning cohort. The number of psychiatric problems was not correlated with early autistic symptoms but was predicted to a small extent by early verbal/non-verbal IQ discrepancy scores. These data indicate that high-functioning PDD children are at greater risk for mood and anxiety problems than the general population but the correlates and risk factors for these comorbid problems remain unclear.
We examined the distribution of ages of onset of autism and related communication handicaps and assessed factors related to age of onset. Subjects were approximately 1,800 children seen at Division TEACCH (Treatment and Education of Autistic and related Communication handicapped CHildren) since 1970. Exact numbers of subjects varied with different analyses due to missing data. Data were gathered through direct assessment, interview, and questionnaire. Seventy-six percent of autistic children were identified by parents by 24 months of age, and 94% by 36 months. Families reporting early onset tended to seek help sooner and to be seen by TEACCH sooner. Early onset was most clearly related to severity as measured by IQ and ratings on the Childhood Autism Rating Scale (Schopler, Reichler, & Renner, 1986). The findings support the treatment of age of onset of autism by DSM-III-R (American Psychiatric Association, 1987).