Veterinary Abstracts
Behaviorial Considerations
J Am Vet Med Assoc. 2001; 219(1):51-6 (ISSN: 0003-1488)
Effect of gonadectomy on subsequent development of age-related cognitive impairment in dogs.
Hart BL, Behavior Service, Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University
of California, Davis, CA 95616, USA.
OBJECTIVE: To determine whether gonadectomy predisposes dogs to development of age-related behavioral changes linked to cognitive impairment. DESIGN: Cohort study. ANIMALS: 29 sexually intact male dogs, 63 spayed female dogs, and 47 castrated male dogs 11 to 14 years old.
PROCEDURE: Information on possible impairments in 4 behavioral categories linked to cognitive impairment (orientation in the home and yard, social interactions, house training, and sleep-wake cycle) was obtained from owners of the dogs by use of a structured telephone interview format. A second interview was performed 12 to 18 months after the initial interview, and differences in responses were evaluated.
RESULTS: Sexually intact male dogs were significantly less likely than neutered dogs to progress from mild impairment (i.e., impairment in 1 category) to severe impairment (i.e., impairment in > or = 2 categories) during the time between the first and second interviews. This difference was not attributable to differences in ages of the dogs, duration of follow-up, or the owners' perceptions of the dogs' overall health.
CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the presence of circulating testosterone in aging sexually intact male dogs may slow the progression of cognitive impairment, at least among dogs that already have signs of mild impairment. Estrogens would be expected to have a similar protective role in sexually intact female dogs; unfortunately, too few sexually intact female dogs were available for inclusion in the study to test this hypothesis. There may be a need to evaluate possible methods for counteracting the effects of loss of sex hormones in gonadectomized dogs.
PRESENTATION SUMMARY POWERPOINT
Non-reproductive
Effects of Spaying and Neutering on Behavior
in Dogs. Deborah L. Duffy, Ph.D.,
and James A. Serpell, Ph.D., Center for
the Interaction of Animals
and Society, School of Veterinary Medicine,
University of Pennsylvania
Although
there are scattered reports in the literature
of apparently adverse effects of spaying
and neutering on canine behavior, there
are very few quantitative studies and
most of these have employed behavioral
measures of unknown reliability and validity.
The present study used the Canine Behavioral
Assessment and Research Questionnaire(C-BARQ)
to investigate the impact of spaying/neutering
in various dog populations, including
(1)
a random sample of 1,552 dogs belonging
to 11 common breeds and (2) a convenience
sample of over 6,000 dogs of various
breeds recruited via an online survey.
The C-BARQ is a reliable, standardized
method for evaluating and screening dogs
for the presence and severity of behavioral
problems. It was developed by behavioral
researchers at the University of Pennsylvania
(Hsu and Serpell, 2003) and consists
of a 101-item questionnaire that is simple
to use, takes about 15 minutes to fill
out, and can be completed by anyone who
is reasonably familiar with the dog’s
typical responses to ordinary, day-to-day
events and stimuli. The C-BARQ is currently
the only existing behavioral assessment
instrument of its kind to be thoroughly
tested for reliability and validity on
large samples of dogs of various breeds.
This process has resulted in the identification
of the following 13 distinct behavioral
factors or traits that are common to
the majority of dogs, regardless of breed,
age, sex or neuter status: 1. Stranger-directed
aggression: Dog shows threatening
or aggressive responses to strangers
approaching or invading the dog’s
or the owner’s
personal space, territory, or home range.
2. Owner-directed
aggression: Dog shows threatening
or aggressive responses to the owner
or other members of the household
when challenged, manhandled, stared
at, stepped over, or when approached
while in possession of food or objects.
3. Dog-directed
fear/aggression: Dog shows
fearful and/or aggressive responses
when approached directly by unfamiliar
dogs. 4. Familiar
dog aggression: Threatening
or aggressive responses during competition
for resources with other (familiar) dog(s)
in the household. 5. Stranger-directed
fear: Fearful or wary responses
when approached directly by strangers.
6. Nonsocial
fear: Fearful or wary responses
to sudden or loud noises, traffic, and
unfamiliar objects and situations. 7. Separation-related
behavior: Vocalizes and/or
engages in destructive behavior when
separated from the owner, often accompanied
or preceded by behavioral and autonomic
signs of anxiety, including restlessness,
loss of appetite, trembling, and excessive
salivation. 8. Attachment
and attention-seeking: Maintains
close proximity to the owner or other
members of the household, solicits
affection or attention, and becomes
agitated when the owner gives attention
to third parties. 9. Trainability: Shows
willingness to attend to the owner, obeys
simple commands, fetches objects, responds
positively to correction, and ignores
distracting stimuli. 10. Chasing: Pursues
cats, birds, and other small animals,
given the opportunity. 11. Excitability: Strong
reaction to potentially exciting or arousing
events, such as going for walks or car
trips, doorbells, arrival of visitors,
and the owner arriving home; difficulty
settling down after such events. 12. Touch
sensitivity: Fearful or wary
responses to potentially painful procedures,including
bathing, grooming, claw-clipping, and
veterinary examinations.
13. Energy
level: Highly
energetic, boisterous, and/or playful
behavior. The
results of the study suggest that spayed
female dogs tend to be more aggressive
toward their owners and to strangers
than intact females, but that these
effects of spaying on behavior appear
to be highly breed-specific. Contrary
to popular belief, the study found
little evidence that castration was an
effective treatment for aggressive
behavior in male dogs, and may exacerbate
other behavioral problems. Further
research will be needed to clarify
the relationship between age of spaying/neutering
and these apparent effects on behavior.
J
Am Vet Med Assoc. 2004 Feb 1;224(3):372-9.
Long-term risks and benefits
of early-age gonadectomy in cats. Spain
CV, Scarlett
JM, Houpt
KA. Department of Population Medicine
and Diagnostic Science, College of Veterinary
Medicine, Cornell University, Ithaca,
NY 14853, USA.
OBJECTIVE: To evaluate the long-term risks and benefits of early-age gonadectomy, compared with traditional-age gonadectomy, among cats adopted from a large animal shelter. DESIGN: Retrospective cohort study.
ANIMALS: 1,660 cats.
PROCEDURE: Cats underwent gonadectomy and were adopted from an animal shelter before 1 year of age; follow-up was available for as long as 11 years after surgery (median follow-up time, 3.9 years). Adopters completed a questionnaire about their cats' behavior and medical history. When possible, the cats' veterinary records were reviewed. Statistical analyses were conducted to identify any associations between the occurrence of 47 medical and behavioral conditions and the cats' age at gonadectomy.
RESULTS: Among male cats that underwent early-age gonadectomy (< 5.5 months of age), the occurrence of abscesses, aggression toward veterinarians, sexual behaviors, and urine spraying was decreased, whereas hiding was increased, compared with cats that underwent gonadectomy at an older age. Among male and female cats that underwent early-age gonadectomy, asthma, gingivitis, and hyperactivity were decreased, whereas shyness was increased.
CONCLUSIONS AND
CLINICAL RELEVANCE: Gonadectomy
before 5.5 months of age was not associated
with increased rates of death or relinquishment
or occurrence of any serious medical
or behavioral condition and may provide
certain important long-term benefits,
especially for male cats. Animal shelters
can safely gonadectomize cats at a young
age, and veterinarians should consider
recommending routine gonadectomy for
client-owned cats before the traditional
age of 6 to 8 months.
PMID: 14765796 [PubMed - indexed for
MEDLINE]
Vet
J. 2006 Jul;172(1):154-9.
Effects of ovariohysterectomy
on reactivity in German Shepherd dogs.
Kim
HH, Yeon
SC, Houpt
KA, Lee
HC, Chang
HH, Lee
HJ. Institute of Animal Medicine,
College of Veterinary Medicine, Gyeongsang
National University, Jinju 660-701, Republic
of Korea.
This study investigated the effects
of ovariohysterectomy on reactivity
of German Shepherd dogs. Fourteen
healthy dogs ranging in age from 5
to 10 months were assigned to an ovariohysterectomy
or a sexually intact group. Their
behaviours were digitally video recorded
4-5 months after treatment and analysed
for treatment effects on reactivity.
Responses to the approach of an unfamiliar
human leading an unknown dog were
assigned the following reactivity
scores: severe reactivity, 3; moderate
reactivity, 2; defensive or mild reactivity,
1; attentive or no reactivity, 0.
Median reactivity scores in response
to the approach of an unfamiliar human
walking with an unknown dog were calculated
for each observation period. Dogs
in the ovariohysterectomized group
showed more reactivity, and median
reactivity scores were higher in the
ovariohysterectomy group compared
with those of the sexually intact
group. Ovariohysterectomy of 5-10
month old German Shepherd bitches
specifically, and perhaps bitches
of any breed generally, may induce
an increase in reactivity. Practitioners
may benefit from recognizing that
a range of behavioural changes may
occur post-ovariohysterectomy.
PMID: 16772140 [PubMed - indexed for
MEDLINE