Veterinary Abstracts
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I. General Health Considerations
Proceedings of the Third International Symposium on Non-Surgical
Contraceptive Methods for Pet Population Control 2006• www.acc-d.org
Risks and Benefits of Neutering and Early-Age Neutering in
Dogs and Cats: Effects on Development, Obesity, and Select
Orthopedic and Neoplastic Conditions
C. Victor Spain, Philadelphia, Pennsylvania
Neutering of dogs and cats confers a mix of benefits and adverse risks.
The objective of this presentation is to highlight recent research findings on
the associations between neutering (whether early-age or at a traditional
age) and select medical conditions. In this abstract, the term neutering is
used in the broadest sense to include both castration of male dogs and
cats or ovariohysterectomy (or ovariectomy) of female dogs and cats.
The
data on early-age neutering is from a retrospective cohort study of 1,579
cats and 1,659 dogs adopted from a large animal shelter between 1989
and 1998 (Spain, 2004). Obesity. Several studies have indicated an
increased prevalence of obesity in neutered dogs and cats. Energy
consumption appears to decrease after neutering in dogs and cats,
although the degree and timing varied between studies. Some
researchers attribute neutering-related obesity in cats to increased food
consumption and not to altered metabolic rate, suggesting that the
weight gain can be prevented with a lower fat diet (German, 2006,
Nguyen, 2004, Kanchuck, 2002). Obesity does not appear to be affected
by age of neutering in cats, but among dogs, early-age neutering is
associated with a lower incidence of obesity than neutering after 6
months of age (Spain, 2004). Canine Hip Dysplasia (CHD) and Cranial
Cruciate Ligament (CCL) Injury. One study found an increased incidence
of CHD after neutering in boxers (van Hagen, 2005), and among dogs
seen in an orthopedic surgical clinic, the prevalence of CCL injury among
neutered dogs (4.7%) was more than twice that of intact dogs (2.3%)
(Slauterbeck, 2004). These findings regarding CCL injury incidence are
consistent with findings that the level of sex hormones affects the
incidence of anterior cruciate ligament (ACL) rupture in humans. Hip
dysplasia is increased among early-neutered dogs compared to those
neutered after 6 months of age (Spain, 2004). Mammary Cancer and
Prostatic Cancer. Spaying before 1 year of age reduces the risk of
mammary carcinoma approximately 90% in cats, and spaying before
second estrus in dogs similarly reduces the risk by about 90% (Overley,
2005). The incidence of mammary cancers does not vary between
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ovariohysterectomy (traditional spay with removal of the uterus and
ovaries) and ovarioectomy (removal of just the ovaries) (van Goethem,
2006). Traditional thought is that neutering reduces the risk of prostatic
cancer
among male dogs. Recent research suggests that after neutering,
however, changes in endothelin, a cell protein involved in cell growth,
may eventually reverse the benefits of neutering on prostatic cancer risk
(Padley, 2002) and the incidence of prostatic cancer may actually be
higher in castrated dogs than intact dogs (Teske, 2002).
Select References
Early-age neutering
CV Spain, JM Scarlett, KA Houpt, 2004. Long-term risks and benefits of
pediatric
gonadectomy in cats. Journal of the American Veterinary Medical
Association. 224(3):372-379. CV Spain, JM Scarlett, KA Houpt, 2004. Longterm risks and benefits of pediatric gonadectomy in dogs. Journal of the
American Veterinary Medical Association . 224(3):380-387. CV Spain, JM
Scarlett, SM Cully, 2002. When to neuter dogs and cats: a survey of New
York state veterinarians’ practices and beliefs. Journal of the American
Animal Hospital Association, 38(4): 482-488.
Physical development and obesity
M Hoenig, DC Ferguson, 2002. Effects of neutering on hormonal
concentrations and energy requirements in male and female cats.
American Journal of Veterinary Research. 63(5): 634-639. AJ German.
2006. The growing problem of obesity in dogs and cats. Journal of
Nutrition.136: 1940S-1946S.
PG Nguyen, HJ Dumon, BS Siliart, et al. 2004. Effects of dietary fat and
energy on body weight and composition after gonadectomy in cats.
American Journal of Veterinary Research. 65(12):1708-1713. ML Kanchuck,
RC Backus, CC Calvert, et al., 2002. Neutering induces changes in food
intake, body weight, plasma insulin and leptin concentrations in normal
and lipoprotein lipase-deficient male cats. Journal of Nutrition. 132:1730S1732S. PD McGreevy, PC Thompson, C Pride, et al., 2005. Prevalence of
obesity in dogs examined by Australian veterinary practices and the risk
factors involved. The Veterinary Record. 156:695-702.
Orthopedic disorders
JR Slaughterbeck, K Pankratz, KT Xu, et al. 2004. Canine
ovariohysterectomy and orchiectomy increases the prevalence of ACL
injury. Clinical Orthopedics and Related Research. 429: 301-305. MAE van
Hagen, BJ Ducro, J van den Broek, et al., 2005. Incidence, risk factors, and
heritability estimates of hind limb lameness caused by hip dysplasia in a
birth cohort of Boxers. American Journal of Veterinary Research. 66(2):307312.
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Mammary and prostate cancer
RJ Padley, DB Dixon, JR Wu-Wong, 2002. Effects of castration on
endothelin receptors. Clinical Science. 103(suppl. 48):442S-445S. B Overley,
FS Shofer, MH Goldschmidt, et al., 2005. Association between
ovariohysterectomy and feline mammary cancer. Journal of Veterinary
Internal
Medicine. 19:560-563. B van Goethem, A Schaefers-Okkens, J Kirpensteijn,
2006. Making a rational choice between ovariectomy and
overiohysterectomy in the dog: A discussion of the benefits of either
technique. Veterinary Surgery. 35:136-143. E Teske, EC Naan, EM van Dijk,
et al., 2002. Canine prostate carcinoma: epidemiologic evidence of an
increased risk in castrated dogs. Molecular and Cellular Endocrinology.
197:251-255.
Journal of the American Veterinary Medical Association 224(3): 380-387.
ISSN: 0003-1488. Spain, C., J. Scarlett, and K. Houpt (2004).
Long-term risks and benefits of early-age gonadectomy in dogs.
NAL Call Number: 41.8 Am3
Abstract: OBJECTIVE: To evaluate the long-term risks and benefits of
early-age gonadectomy, compared with traditional-age gonadectomy,
among dogs adopted from a large animal shelter. DESIGN: Retrospective
cohort study. ANIMALS: 1,842 dogs. PROCEDURE: Dogs 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.
Adopters completed a questionnaire about their dogs' behavior and
medical history. When possible, the dogs' veterinary records were
reviewed. Associations between the occurrence of 56 medical and
behavioral conditions and dogs' age at gonadectomy were evaluated.
RESULTS: Among female dogs, early-age gonadectomy was associated
with increased rate of cystitis and decreasing age at gonadectomy was
associated with increased rate of urinary incontinence. Among male and
female dogs with early-age gonadectomy, hip dysplasia, noise phobias,
and sexual behaviors were increased, whereas obesity, separation
anxiety, escaping behaviors, inappropriate elimination when frightened,
and relinquishment for any reason were decreased. CONCLUSIONS AND
CLINICAL RELEVANCE: Because early-age gonadectomy appears to offer
more benefits than risks for male dogs, animal shelters can safely
gonadectomize male dogs at a young age and veterinary practitioners
should consider recommending routine gonadectomy for client-owned
male dogs before the traditional age of 6 to 8 months. For female dogs,
however, increased urinary incontinence suggests that delaying
gonadectomy until at least 3 months of age may be beneficial.
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II. Orthopedic Considerations
J Am Vet Med Assoc. 1991 Apr 1;198(7):1193-203
Gonadectomy in immature dogs: effects on skeletal, physical, and
behavioral development.
Salmeri KR, Bloomberg MS, Scruggs SL, Shille V.
Department of Small Animal Clinical Sciences, University of Florida,
Gainesville 32610-0126.
In a 15-month study, the effects of prepubertal gonadectomy on skeletal
growth, weight gain, food intake, body fat, secondary sex characteristics,
and behavioral development were investigated in 32 mixed-breed dogs.
Male and female pups from 5 litters were randomly allotted to 3 groups:
group I, neuter at 7 weeks (n = 14); group II, neuter at 7 months (n = 8);
and group III, sexually intact dogs (n = 10). Growth plate closure was
delayed (group I vs group III; P less than 0.000001; group II vs group III, P
less than 0.000001) in all neutered dogs, as compared with sexually intact
dogs. Growth plate closure was delayed longer (group I vs group II, P less
than 0.000045) in dogs neutered at 7 weeks old, compared with dogs
neutered at 7 months old. The rate of growth was unaffected by
gonadectomy, but the extended growth period resulted in greater final
radial/ulnar length in all male dogs and bitches neutered at 7 weeks.
Gonadectomy did not influence food intake, weight gain, or back-fat
depth. Penile development was immature in the adult group-I males
(mean +/- SEM diameter of pars glandis = 11.1 +/- 1.0 mm), compared
with adult group-II (16.3 +/- 0.5 mm) and group-III (21.0 +/- 2.2 mm) males.
Subjectively, the prepuce and os penis of the group-I males were
immature, compared with those of group-II and group-III males. Vulvar
development in group-I and group-II bitches was less mature than vulvar
development in the sexually intact bitches. Of 7 behavioral characteristics
assessed, only general activity and excitability rated differently among
treatment groups. All neutered dogs were judged to be more active
(group I, P less than 0.004) than sexually intact dogs. Group-I males were
judged to be more excitable (P less than 0.02) than group-III males. It was
concluded that with respect to skeletal, physical, and behavioral
development, the effect of neutering pups at 7 weeks old was similar to
that of neutering pups at 7 months old.
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Am J Vet Res. 2005; 66(2):307-12 (ISSN: 0002-9645)
Incidence, risk factors, and heritability estimates of hind limb lameness
caused by hip dysplasia in a birth cohort of boxers. van Hagen MA
; Ducro BJ ; van den Broek J ; Knol BW, Department of Clinical Sciences of
Companion Animals, Faculty of Veterinary Medicine, Utrecht University,
P.O. Box 80154, 3508 TD Utrecht, The Netherlands.
OBJECTIVE: To determine incidence, risk factors, and heritability estimates
of hind limb lameness caused by hip dysplasia in a birth cohort of Boxers.
ANIMALS: 1733 Boxers from 325 litters. PROCEDURE: Status of Boxers with
respect to clinical signs of canine hip dysplasia (cCHD) was registered
during an 8-year period. Survival analysis accounted for dogs lost to
follow-up. Effective heritability for developing cCHD was estimated by use
of a proportional hazard model on the basis of the Weibull distribution.
Parametric survival models were developed to identify the influence of
potential risk factors. RESULTS: Cumulative hazard rate for cCHD from 7
weeks to 8 years of age was 8.5%. Dogs that were kept on a floor covered
with a slippery material were 1.6 times as likely to develop cCHD,
compared with dogs kept on a nonslippery floor. Risk of cCHD doubled in
dogs from litters with a high preweaning mortality rate. Dogs that were
neutered at 6 months prior to a diagnosis of CHD were 1.5 times as likely to
develop cCHD, compared with sexually intact dogs. Dogs >5 years of age
were 1.8 times as likely to develop cCHD, compared with younger dogs.
Estimated effective heritability of cCHD was 0.11. In terms of the risk of
cCHD in progeny, mean estimated breeding value (EBV) of the 10 best
and 10 worst sires was -0.32 and 0.42, respectively. CONCLUSIONS AND
CLINICAL RELEVANCE: Registration of Boxers that develop cCHD may
provide a strategy for disease prevention. In addition to diagnostic
evaluation of radiographs, sire EBVs provide useful information for
breeding selection decisions.
J Am Vet Med Assoc, 203(7): 1016-9 1993
Epidemiology of cranial cruciate ligament rupture in dogs.
Whitehair JG , Vasseur PB , Willits NH
Abstract: Data from 10,769 dogs with rupture of the cranial cruciate
ligament (CCL) were compared with data from a control population of
591,548 dogs to determine whether age, breed, gender, or body weight
was associated with prevalence of CCL rupture. Prevalence of CCL
rupture increased as dogs became older, with peak prevalence in dogs 7
to 10 years old. Among breeds represented by > 1,000 individuals,
Rottweilers, Newfoundlands, and Staffordshire Terriers had the highest
prevalence of CCL rupture, whereas Dachshunds, Basset Hounds, and Old
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English Sheepdogs had the lowest. Neutered dogs, whether male or
female, had a higher prevalence of CCL rupture than did sexually intact
dogs. The dog's age at the time of ovariohysterectomy was not
associated with prevalence of CCL rupture. Dogs weighing > 22 kg had a
higher prevalence of CCL rupture, compared with dogs weighing < 22 kg,
and tended to rupture their CCL at a younger age.
J Am Vet Med Assoc. 1993; 203(7):1016-9 (ISSN: 0003-1488)
Epidemiology of cranial cruciate ligament rupture in dogs. Whitehair JG
; Vasseur PB ; Willits NH, Veterinary Medical Teaching Hospital, Department
of Surgery, School of Veterinary Medicine, University of California, Davis
95616.
Data from 10,769 dogs with rupture of the cranial cruciate ligament (CCL)
were compared with data from a control population of 591,548 dogs to
determine whether age, breed, gender, or body weight was associated
with prevalence of CCL rupture. Prevalence of CCL rupture increased as
dogs became older, with peak prevalence in dogs 7 to 10 years old.
Among breeds represented by > 1,000 individuals, Rottweilers,
Newfoundlands, and Staffordshire Terriers had the highest prevalence of
CCL rupture, whereas Dachshunds, Basset Hounds, and Old English
Sheepdogs had the lowest. Neutered dogs, whether male or female, had
a higher prevalence of CCL rupture than did sexually intact dogs. The
dog's age at the time of ovariohysterectomy was not associated with
prevalence of CCL rupture. Dogs weighing > 22 kg had a higher
prevalence of CCL rupture, compared with dogs weighing < 22 kg, and
tended to rupture their CCL at a younger age.
Calcif Tissue Int. 1998; 62(3):237-43 (ISSN: 0171-967X)
Ovariectomy-induced changes in aged beagles: histomorphometry of rib
cortical bone. Wilson AK ; Bhattacharyya MH ; Miller S ; Mani A ; SaccoGibson N, Center for Mechanistic Biology and Biotechnology, Argonne
National Laboratory, Illinois 60439, USA.
Bone loss associated with estrogen depletion is well documented in
cancellous bone but less well characterized in cortical bone. The effects
of ovariectomy on the aged beagle skeleton were studied by
histomorphometric analysis of the cortical bone in sequential rib biopsies.
Biopsies were taken from each ovariectomized or sham-operated dog at
the time of surgery and at 1, 4, and 8.5 months after surgery. Just prior to
each postoperative biopsy, tetracycline, calcein, and xylenol orange,
respectively, were administered by a fluorochrome labeling procedure
(2d-10d-2d) to provide markers of bone formation. Analysis of sequential
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rib biopsies provided a means to follow the ovariectomy response over
time and to compare each animal against its own baseline. Though
ovariectomy did not influence histomorphometric indices at 1 month after
surgery, a transient increase in cortical bone formation occurred
thereafter, with a sixfold increase over that of sham-operated dogs at 4
months (P < 0.001) and a return to near control levels at 8.5 months.
Cortical porosity increased by the fourth month after ovariectomy and
remained high at 8.5 months. These data demonstrate for the first time
that rib cortical bone is a responsive site for the effects of ovariectomy in
aged female dogs.
III. Cancer Considerations
Vet J. 1998 Jul;156(1):31-9.
Host related risk factors for canine osteosarcoma.
Ru G, Terracini B, Glickman LT.
Department of Animal Pathology, University of Turin, Italy.
A case-control study using the Veterinary Medical Data Base (VMDB) was
conducted to test the hypothesis that increasing height and increasing
weight are important risk factors for osteosarcoma in dogs. The role of
other host factors was also explored. The cases comprised 3062 purebred
dogs with histologically or radiographically confirmed osteosarcoma
admitted to 24 veterinary teaching hospitals in the United States and
Canada between 1980 and 1994. The controls were 3959 purebred dogs
with other diagnoses obtained randomly by frequency matching to cases
for institution and year of diagnosis. The risk of osteosarcoma rose with
increasing age, increasing body weight, increasing standard weight and
increasing standard height. Compared with the German Shepherd breed,
the highest risk of osteosarcomas was found for large and giant breeds,
while small breeds had reduced risks. A twofold excess risk was observed
among neutered dogs. Adjustment of risk estimates for standard height
adjusted for standard weight, and vice versa, showed a stronger and
more consistent association of osteosarcoma with increasing height than
increasing weight.
Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1434-40.
Endogenous gonadal hormone exposure and bone sarcoma risk.
Cooley DM, Beranek BC, Schlittler DL, Glickman NW, Glickman LT, Waters
DJ., Department of Veterinary Clinical Sciences, Purdue University, West
Lafayette, Indiana 47907, USA.
Although experimental and clinical evidence suggest that endogenous
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sex hormones influence bone sarcoma genesis, the hypothesis has not
been adequately tested in an appropriate animal model. We conducted
a historical cohort study of Rottweiler dogs because they frequently
undergo elective gonadectomy and spontaneously develop
appendicular bone sarcomas, which
mimic the biological behavior of the osteosarcomas that affect children
and adolescents. Data were collected by questionnaire from owners of
683 Rottweiler dogs living in North America. To determine whether there
was an association between endogenous sex hormones and risk of bone
sarcoma, relative risk (RR) of incidence rates and hazard ratios for bone
sarcoma were calculated for dogs subdivided on the basis of lifetime
gonadal hormone exposure. Bone sarcoma was diagnosed in 12.6% of
dogs in this cohort during 71,004 dog-months follow-up. Risk for bone
sarcoma was significantly influenced by age at gonadectomy. Male and
female dogs that underwent gonadectomy before 1 year of age had an
approximate one in four lifetime risk for bone sarcoma and were
significantly more likely to develop bone sarcoma than dogs that were
sexually intact [RR +/-95% CI = 3.8 (1.5-9.2) for males; RR +/-95% CI = 3.1
(1.1-8.3) for females]. Chi(2) test for trend showed a highly significant
inverse dose-response relationship between duration of lifetime gonadal
exposure and incidence rate of bone sarcoma (P = 0.008 for males, P =
0.006 for females). This association was independent of adult height or
body weight. We conclude that the subset of Rottweiler dogs that
undergo early gonadectomy represent a unique, highly accessible target
population to further study the gene:environment interactions that
determine bone sarcoma risk and to test whether interventions can inhibit
the spontaneous development of bone sarcoma
Vet Intern Med 1987 Oct-Dec;1(4):183-7 Related Articles, Books
The influence of castration on the development of prostatic carcinoma in
the dog: 43 cases (1978-1985) Obradovich J, Walshaw R, Goullaud E
Department of Small Animal Clinical Sciences, College of Veterinary
Medicine, Michigan State University, East Lansing 48824.
Prostatic carcinoma (PC) was diagnosed in 43 dogs at the Michigan State
University Veterinary Clinical Center (MSU-VCC) between 1978 and
1985. Of the 43 dogs with histologically confirmed PC, 19 (44.19%) had
been castrated at least three years prior to the development of any
prostatic disease. Seven of the castrates had been neutered at less than
12 months of age. Fourteen dogs (32.55%) were presented as intact
males at the time of diagnosis. The remaining ten dogs (23.62%) had
been castrated as treatment for presumptive prostatic disease prior to
referral to the MSU-VCC. Dates of castration were known in all cases. In
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this study, therefore, castration at any age showed no sparing effect on
the risk of development of PC in the dog. The etiology of PC in the dog
may not be exclusively related to testicular hormones. Work in humans
suggests that the adrenal and pituitary glands play a significant role in the
disease. Preliminary work in dogs supports that nontesticular androgens
exert a significant influence on the canine prostate.
Acta Anat (Basel) 1984;120(3):103-7 Related Articles, Books
Early changes in the dog prostate after castration. An ultrastructural study.
Sinowatz F
Using electron microscopic techniques the prostate glands of male
Beagle dogs were studied 3 days after castration. At this time marked
differences in the extent of alterations of the glandular epithelium were
observed: Whereas several acini showed only minor changes with
reduction of epithelial height and diminution of secretory granules, many
acini were severely affected with pronounced alteration of cellular
structure and accumulation of large lipid droplets. A constant feature
was the stimulation of the basal cells of the grandular
epithelium. Additionally, in some areas of the gland aggregations of
stimulated basal cells forming an acinus-like structure with a slit-like lumen
were found. Our study shows that castration leads to marked alterations
of prostatic epithelium within a short time. Androgen deprivation causes
regressive changes of secretory epithelial cells, but clearly stimulates the
basal cell population.
J Vet Intern Med 1999 Mar-Apr;13(2):95-103
Cardiac tumors in dogs: 1982-1995. Ware WA, Hopper DL.
A Veterinary Medical Database search from 1982 to 1995 identified 1,383
dogs with tumors of the heart from a total population of 729,265 dogs
(0.19% incidence). Hemangiosarcoma (HSA) was the most common
cardiac tumor identified. In the subset of dogs with specific histologic
diagnoses, the number with HSA was almost 10-fold that of the 2nd most
common tumor, aortic body tumor. Primary heart tumors were more
common than cardiac metastases. When biologic behavior was noted,
most heart tumors were classified as malignant. Cardiac tumors
(excluding lymphoma) occurred most often in dogs between the ages of
7 and 15 years. In very old dogs (>15 years), the frequency of cardiac
tumors was the same or lower than that of the youngest age group.
Tumors occurred with similar frequency in males and females, but the
relative risk for spayed females was >4 times that for intact females. For
HSA, spayed females had >5 times greater relative risk than did intact
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females. The risk for castrated males was slightly greater than that for
intact males, which had 2.4 times the relative risk of intact females. Thus,
neutering appeared to increase the risk of cardiac tumor in both sexes.
Intact females were least likely to develop a cardiac tumor, whereas
spayed females were most likely to develop a tumor. Twelve breeds had
greater than average risk of developing a cardiac tumor, whereas 17 had
lower risk.
Source: J Vet Intern Med, 6(3): 145-53 1992
Canine bladder and urethral tumors: a retrospective study of 115 cases
(1980-1985).
Norris AM , Laing EJ , Valli VE , Withrow SJ , Macy DW , Ogilvie GK ,
Tomlinson J , McCaw D , Pidgeon G , Jacobs RM
Abstract: One hundred and fifteen dogs with neoplasms of the lower
urinary tract (bladder and/or urethra) were retrospectively evaluated at
five referral institutions participating in ongoing studies by the Veterinary
Cooperative Oncology Group. Most tumors were malignant (97%) and of
epithelial origin (97%). Lower urinary tract tumors were more common in
older dogs weighing greater than 10 kg. The following significant (P less
than 0.05) statistical associations were found using the University of Guelph
hospital population as control; there was no sex predisposition although
the female:male ratio was 1.95:1. Neutered dogs were predisposed as
were Airedale Terriers, Beagles, and Scottish Terriers, whereas German
Shepherds were significantly under-represented among dogs with lower
urinary tract tumors. These statistical associations should be interpreted
cautiously because of possible demographic differences in hospital
populations among the University of Guelph and other cooperating
institutions. There were no significant correlations between age, gender,
weight, breed, response to therapy, and survival time. Clinical signs were
indicative of lower urinary tract disease and included hematuria,
stranguria, and pollakiuria. The laboratory data were nonspecific except
for urinalysis test results. Hematuria and inflammatory urinary sediments
were most commonly reported; neoplastic cells were identified in the
urine sediment of 30% of dogs with lower urinary tract tumors. Contrast
cystography was a useful noninvasive diagnostic method since 96% of the
dogs had a mass or filling defect in the lower urinary tract demonstrated
by this technique.
J Am Vet Med Assoc, 200(8): 1119-22 1992
Study of prostatic disease in dogs: 177 cases (1981-1986).
Krawiec DR , Heflin D
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Abstract: Historical and physical signs associated with prostatic disease
diagnosed in dogs over a 5.5-year period were defined. One hundred
seventy-seven male dogs were determined to have prostatic abnormality.
Of the 177 dogs, 87 were determined to have specific prostatic disease.
The most common prostatic disease identified in this study was bacterial
prostatitis, followed by prostatic cyst, prostatic adenocarcinoma, and
benign hyperplasia. The most common prostatic disease identified in
neutered dogs was prostatic adenocarcinoma. Mean age at onset of
prostatic disease was 8.9 years; statistically significant difference was not
observed between age at onset of the various types of prostatic disease
identified. Doberman Pinscher was the most common breed with prostate
disease. Twenty-nine percent of dogs with a specifically identifiable
prostatic disease had signs of systemic illness, 41% had signs of lower
urinary tract disease, 28% had signs of gastrointestinal tract abnormalities,
and 13% had signs of locomotor difficulty.
IV. Incontinence Considerations
Proceedings of the Third International Symposium on Non-Surgical
Contraceptive Methods for Pet Population Control 2006• www.acc-d.org
Incontinence in Spayed Bitches: Frequency, Causes & Therapy
Iris Reichler, Madeleine Hubler and Susi Arnold, Vetsuisse-Faculty, University
of Zurich, Switzerland
Urinary incontinence (UI) is the involuntary loss of urine. UI rarely occurs in
sexually intact bitches (0-1%)1, whereas in spayed bitches the incidence is
up to 20%2. The underlying pathophysiological mechanism is a reduced
closure pressure of the urethra after spaying 3.
The causal relationship between the removal of the ovaries and UI has
been clearly demonstrated 4. However, it is still unclear what mechanism
triggers UI after spaying. An oestrogen deficiency was initially considered
to be the underlying cause5. This hypothesis is however contradicted by
several observations. For example, bitches treated with depot
preparations of gestagens, to suppress oestrus, do not have an increased
risk of UI, even though the treatment results in ovarian atrophy6 and the
oestrogen remains in a basal level 7. Another side effect of spaying is the
increase in plasma gonadotropins, due to the lack of the ovarian
negative feedback 8. About 42 weeks after ovarectomy the
gonadotropin levels reach a plateau, when the plasma FSH is 17 times
and the plasma LH is 8 times the initial concentration 9. One could
therefore ask if it is the elevated plasma level of FSH and LH that are
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responsible for the increased risk of UI in spayed bitches. If this were
correct, then affected bitches could be successfully treated with depot
preparations of GnRHanalogues, through down-regulation of GnRHreceptors in the pituitary and this in turn will decrease the plasma
gonadotropin concentrations. Indeed, 7 of 13 bitches affected by UI were
successfully treated with an injection of depot preparations of GnRHanalogues and remained continent for an average of 247 days10.
However, it is questionable whether the success of this treatment is due to
a decrease in gonadotropins since their blood levels in responders and
non-responders are not different11. It is possible that GnRH has a
directeffect on the lower urinary tract, but the success of the therapy is
not based on a normalisation of the urethral sphincter incompetence
after spaying11. Recent studies in beagle bitches have given rise to the
assumption that GnRH modulates the function of the bladder12. The
treatment of incontinent bitches with GnRH-analogues is mainly interesting
for the clarification of the pathophysiological mechanism. For patients
affected by UI, the therapy of first choice is with alpha-adrenergica
(Phenylpropanolamine / Ephedrine). This results in an increased urethral
closure pressure and continence in more than 90% of cases. If the
therapeutic effect is insufficient, then alpha-adrenergica may be
combined with oestrogen or Flavoxatum. In refractory cases, several
surgical methods are described ofwhich colposuspension13,
urethropexy14 and the endoscopic injection of collagen15 aremost
common and have a success rate of 50 - 75%.
References1. Thrusfield, Holt and Muirhead (1998) J Small Anim Pract
39:559-566. 2. Arnold et al. (1989) Schweiz Arch Tierheilk 131:259-263. 3.
Rosin and Barsanti (1981) JAVMA 178:814-822. 4. Thrusfield (1985) Vet Rec
116:695. 5. Finco, Osborne and Lewis (1974) Vet Clin North Am 4:501-516.
6. El Etreby (1979) Cell Tissue Res 200:229-243. 7. De Bosschere et al. (2002)
Theriogenology 58:1209-1217. 8. Olson, Mulnix and Nett (1992) Am J Vet
Res 53:762-766. 9. Reichler et al. (2004) Theriogenology 62:1391-1402. 10.
Reichler et al. (2003) Theriogenology 60:1207-1216. 11. Reichler et al.,
Theriogenology, in press (2006). 12. Reichler et al., Theriogenology, in press
(2006). 13. Holt, J Small Anim Pract 26:237-246, 1985. 14. White, J Small
Anim Pract, 42: 481-486, 2001. 15. Arnold et el. (1996) Small Anim Pract
37:163-168.
Journal of Reproduction and Fertility 57(Suppl.): 233-236. ISSN: 0449
3087.
The relationship of urinary incontinence to early spaying in bitches.
Stocklin-Gautschi, N.M., M. Hassig, I.M. Reichler, S. Arnold and M. Hubler
(2001).
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NAL Call Number: 442.8 J8222 Suppl.
Abstract: It is still controversial whether a bitch should be spayed before
or after the first oestrus. It would be desirable to spay bitches at an age
that would minimize the side effects of neutering. With regard to the risk
of mammary tumours, early spaying must be recommended because the
incidence of tumours is reduced considerably. The aim of the present
study was to determine whether early spaying also reduces the risk of
urinary incontinence. The owners of 206 bitches that had been spayed
before their first oestrus and for at least 3 years were questioned on the
occurrence of urinary incontinence as a result of spaying. At the time of
the enquiry the average age of the bitches was 6.5 years, and the
average age at the time of surgery was 7.1 months. Urinary incontinence
after spaying occurred in 9.7% of bitches. This incidence is approximately
half that of spaying after the first oestrus. Urinary incontinence affected
12.5% of bitches that were of a large body weight (> 20 kg body weight)
and 5.1% of bitches that were of a small body weight (< 20 kg body
weight). The surgical procedure (ovariectomy versus ovariohysterectomy)
had no influence on the incidence, or on the period between spaying
and the occurrence of urinary incontinence. Urinary incontinence
occurred on average at 2 years and 10 months after surgery and
occurred each day, while the animals were awake or during sleep.
However, compared with late spaying the clinical signs of urinary
incontinence were more distinct after early spaying.
Schweiz Arch Tierheilkd. 1997; 139(6):271-6 (ISSN: 0036-7281)
Urinary incontinence in castrated bitches. Part 1: Significance, clinical
aspects and etiopathogenesis Arnold S Arnold P ; Hubler M ; Casal M
; Rüsch P, Departement für Fortpflanzungskunde, VeterinärMedizinische Fakultät, Universität Zürich.
Acquired urinary incontinence occurs in 20% of spayed dogs and there
exists a strong correlation between body weight and the risk of urinary
incontinence. Bitches with a body weight of more than 20 kg have a risk
of 30% white smaller dogs have a risk of 10%. A particular breed disposition
exists in Boxers in which 65% are affected. Other breeds with a more than
average disposition for urinary incontinence are Dobermans and Giant
Schnauzers. Urinary incontinence due to spaying manifests itself mainly
while the dogs are sleeping. The cause is a urethral sphincter
incompetence which can be verified by a urethral pressure profile (UPP).
The microtransducer method proved to be a suitable method for
urodynamic studies. It could be demonstrated that the urethral closure
pressure is significantly lower in incontinent bitches (4.6 +/- 2.3 cm H2O)
than in continent bitches (18.6 +/- 10.5 cm H2O). In addition, the urethral
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closure pressure for continent bitches dropped significantly within 12
months after surgery. Histological examination revealed that the
functional urethral closure cannot be explained by the extent of
discernible structures of the urethral wall as seen by light microscopy.
Schweiz Arch Tierheilkd. 1989; 131(5):259-63 (ISSN: 0036-7281)
Urinary incontinence in spayed female dogs: frequency and breed
disposition. Arnold S ; Arnold P ; Hubler M ; Casal M ; Rüsch P
A follow up study was performed in 412 spayed bitches in order to
determine the incidence of urinary incontinence. The period between the
operation being performed and the survey being made varied between 3
and 10 years. 83 animals (20.1%) were incontinent independent of the
surgical procedure (ovariectomy versus ovariohysterectomy). The onset of
incontinence varied between immediately to 12 years with an average
period of 2.9 years after surgery. 57 of these incontinent bitches were
treated with ephedrine or estrogen. In 73.7% a good response was
achieved with ephedrine and a further 23.7% showed some improvement.
Generally ephedrine was more successful than estrogen in the treatment
of incontinence. There appears to be a strong connection between body
weight and the incidence of incontinence. Of bitches with a body weight
of less than 20 kg only 9.3% were incontinent. Whereas in bitches with a
body weight of more than 20 kg the incidence was 30.9%. Of the breeds
Boxers showed a high incidence of incontinence (65%) while breeds such
as German Shepherds (10.6%) or Dachshunds (11.1%) showed a low
incidence in relation to the average incidence rate (20.1%).
Vet Rec. 1997; 141(24):620-5 (ISSN: 0042-4900)
Comparisons between stress incontinence in women and sphincter
mechanism incompetence in the female dog. Janssens LA ; Peeters S
University of Antwerp, Laboratory of Medical Electronics, Belgium.
In dogs, sphincter mechanism incompetence most often affects middleaged spayed bitches and is more prevalent in docked animals, certain
breeds and in dogs over 30 kg in weight. It results in urinary leakage,
mainly when the animal is recumbent and relaxed. In humans, stress
incontinence occurs most often in post-menopausal women who are
multiparous, have had difficult deliveries and are obese. They also leak
urine, but most often when active stressors increase abdominal pressure.
Both women and bitches have shorter functional urethras and lower
maximal urethral pressures. In women, the compliance and crosssectional area of the urethra are increased and power generation is
substantially weakened. Many women and most bitches have an
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intrapelvic bladder neck and a short urethra. Owing to hormonal
deficiencies they have an impaired capacity to seal the lumen of the
urethra and the urethral sphincter is less sensitive to sympathomimetics. In
women partial denervation of the pudendal nerve is also a contributory
factor.
V. Behavioral Considerations
Proceedings of the Third International Symposium on Non-Surgical
Contraceptive Methods for Pet Population Control 2006• www.acc-d.org
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(CBARQ)© 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:
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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. 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
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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.
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
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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
VI. Metabolic Considerations
From the Merck Veterinary Manual 8th Edition Page 416 - The Thyroid
Gland
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Clinical Findings: Although onset is variable, hypothyroidism is most
common in dogs 4-10 years old. It usually affects mid-to large-size breeds
and is rare in toy and miniature breeds. Breeds reported to be
predisposed include the Golden Retriever, Doberman Pinscher, Irish Setter,
Miniature Schnauzer, Dachshund, Cocker Spaniel, and Airedale Terrier.
There does not appear to be a sex predilection, but the risk of developing
hypothyroidism appears to be higher in spayed females than in intact
females.
J Am Vet Med Assoc, 214(1): 46-51 1999
Evaluation of risk factors for fatal acute pancreatitis in dogs.
Hess RS , Kass PH , Shofer FS , Van Winkle TJ , Washabau RJ
Abstract: OBJECTIVE: To identify risk factors associated with fatal acute
pancreatitis in dogs. DESIGN: Case-control study. ANIMALS: 70 case dogs
with clinical evidence and histopathologic confirmation of fatal acute
pancreatitis and 104 control dogs that had trauma, underwent necropsy,
and did not have histologic evidence of acute pancreatitis. PROCEDURE:
Information on signalment, weight, body condition, medical history,
concurrent disease, and results of histopathologic examination was
obtained by reviewing medical records. Logistic regression analysis
included calculation of univariate and multivariate (adjusted) odds ratios
and 95% confidence intervals. RESULTS AND CLINICAL IMPLICATIONS: Dogs
with fatal acute pancreatitis were largely middle- to older-aged dogs. Risk
of developing fatal acute pancreatitis was increased by overweight body
condition, diabetes mellitus, hyperadrenocorticism, hypothyroidism, prior
gastrointestinal tract disease, and epilepsy. Additionally, Yorkshire Terriers
were at increased risk, and Labrador Retrievers and Miniature Poodles
were at decreased risk, of developing fatal acute pancreatitis. Males and
neutered females appeared to have an increased risk of developing fatal
acute pancreatitis, compared with sexually intact females. Thrombus
formation was more likely in dogs that developed fatal acute pancreatitis
than in control dogs.
Am J Vet Res, 43(3): 465-70 1982
Epizootiologic patterns of diabetes mellitus in dogs. Marmor M , Willeberg
P , Glickman LT , Priester WA , Cypess RH , Hurvitz AI
Abstract: A case-control study of spontaneous diabetes mellitus in dogs
was undertaken, using 2 veterinary data bases. The Veterinary Medical
Data Program (VMDP) contained records of 1,019 cases of canine
diabetes from 14 university-affiliated veterinary hospitals. The Animal
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Medical Center (AMC), a private veterinary hospital which has not
participated in the VMDP, contained records of 449 diabetes cases. Each
data base was analyzed separately, control groups being chosen from all
admissions, excluding diabetic animals. Summary odds ratios by sex
adjusted for age and breed indicated significantly (P less than 0.05)
elevated risks for entire females and neutered females compared with
that for entire males. The VMDP data indicated a significantly elevated risk
for castrated males, whereas the risk derived from AMC data was not
significantly different from 1. Analysis of risks by breed adjusting for age
and sex identified Poodles as being at significantly excess risk, and
German Shepherd Dogs, Cocker Spaniels, Collies, and Boxers at
significantly decreased risk in both data sets. The male-female risk ratio
changed with age from 1 at less than 1 year of age to a predominance
of females at older ages. In the AMC data base, diabetes was
significantly associated with cataracts in dogs of both sexes combined.
Diabetes was also significantly associated with benign mammary tumors
in female dogs.
J Anim Physiol Anim Nutr (Berl). 2001 Aug;85(7-8):195-9.
Leptin, body fat content and energy expenditure in intact and
gonadectomized adult cats: a preliminary study. Martin L, Siliart B, Dumon
H, Backus R, Biourge V, Nguyen P. Laboratory of Nutrition and
Endocrinology, National Veterinary School of Nantes, Nantes France.
The present study was conducted to assess the body composition, leptin,
and energy expenditure changes following gonadectomy in cats.
Twenty-one females (12 intact and nine spayed) and 21 males (11 intact
and 10 castrated) were used. Body weight was recorded. Serum plasma
leptin was measured by radioimmunoassay and body composition and
energy expenditure were assessed after injection of doubly labelled
water. These results confirmed the gain in body weight and body fat
following neutering and demonstrated a strong linear relationship
between body fat and serum level of leptin. Energy expenditure
decreased in castrated cats in comparison with intact ones. This study
underlined the effect of gonadectomy as a major factor of obesity in cats
and showed that the increase in circulating leptin reflected the amount of
body fat. The present results provide further evidence that the regimen of
gonadectomized cats should be carefully controlled to avoid excessive
weight gain.
J Anim Physiol Anim Nutr (Berl), 90(9-10): 355-60 2006
Hormonal disturbances associated with obesity in dogs. Martin LJ , Siliart B,
Dumon HJ , Nguyen PG
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Abstract: Obesity is associated with multiple endocrine alterations and
changes in the concentration of circulating hormones. However, few
studies have explored such alterations in dogs with naturally acquired
excess weight. In the present study, we investigated the effect of naturally
acquired obesity on cortisol, insulin-like growth factor (IGF)-1 and prolactin
secretion in dogs. Thirty-one overweight dogs were enrolled in the trial.
Blood samples were collected before and after adrenocorticotrophic
hormone (ACTH) injection. Free thyroxine (fT4), cortisol, thyroid-stimulating
hormone (TSH), IGF-1, prolactin and fructosamine were assayed. Body
weight excess increased significantly with age and neutered dogs were
more obese than entire ones. The ACTH stimulation test was within the
normal range for 26 of 31 dogs. Prolactinaemia was increased in seven
dogs and IGF-1 in six dogs. Twenty dogs had a fructosamine
concentration >340 microm. Interestingly, 18 of 31 dogs showed
disturbances of thyroid function based on high TSH and/or low fT4 baseline
concentration, with 11 dogs showing both. According to these
parameters only six of 31 dogs were free of hormonal disturbances. These
results revealed the high incidence of such disturbances, especially
thyroid dysfunction, in obese, but otherwise apparently healthy dogs. They
demonstrate the importance of examining endocrine function during the
initial evaluation of obese dogs to avoid failure of any nutritional
treatment.
Vet Rec, 118(14): 391-6 1986
Study of obesity in dogs visiting veterinary practices in the United
Kingdom. Edney AT , Smith PM
Abstract: A total of 8268 dogs were surveyed in 11 veterinary practices in
the United Kingdom during a period of six months in 1983. The primary
purpose of the survey was to assess the level of obesity on a five point
scale with properly identified criteria. Information on the clinical condition
of each dog was also recorded as well as proportions of food types fed,
particulars of breed, sex, age, sexual status and the dog's name. Results
showed that 21.4 per cent of dogs in the survey were judged to be obese
and 2.9 per cent gross; 1.9 per cent were judged as thin, 13.5 per cent
lean and 60.3 per cent were optimum. Labradors were found to be the
most likely breed to become obese. Neutered females were about twice
as likely to be obese as entire females. The same trend was evident with
neutered males. Circulatory problems were associated with dogs over 10
years old and those which were gross, rather than obese. A similar trend
was discernable with articular/locomotor problems. Skin and reproductive
problems showed little relationship with age or obesity. Neoplasia was
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much more prevalent in dogs over 10 years old but had little relationship
with either sexual status or obesity rating. There was a high rate of usage
of prepared food for all categories. The amount of fresh food fed
decreased rapidly as the proportion of canned food increased, but the
obese and non-obese dogs showed very little difference in the type of
food fed.
Am J Vet Res. 1996 Mar;57(3):371-4.
Effect of prepuberal and postpuberal gonadectomy on heat production
measured by indirect calorimetry in male and female domestic cats.
Root MV, Johnston SD, Olson PN. Department of Small Animal Clinical
Sciences, College of Veterinary Medicine, University of Minnesota, St Paul
55108, USA.
OBJECTIVE--To use indirect calorimetry to compare heat production
between gonadectomized and sexually intact male and female cats.
DESIGN--Male (n = 6) and female (n = 6) kittens were gonadectomized at
7 weeks or 7 months of age, or left sexually intact. Body heat production
was measured by indirect calorimetry in all cats at 12, 18, and 24 months
of age. ANIMALS--18 male and 18 female clinically normal domestic
shorthair cats. PROCEDURE--Heat production was measured, using an
open-circuit, respiratory, indirect calorimeter. All cats underwent
calorimetry at 12, 18, and 24 months of age. The heat coefficient, a
measure of resting metabolic rate, was calculated for each cat at each
test; heat coefficient is defined as logarithm of heat (kcal/h) divided by
logarithm of body weight (kg). RESULTS--Heat production did not vary with
age in male or female cats. Heat coefficient was higher in sexually intact
male and female cats than in gonadectomized male and female cats at
12, 18, and 24 months of age (12 months, females, P < 0.01, males, P =
0.04; 18 months, females, P < 0.01, males, P = 0.02; and 24 months, females
and males, P < 0.01). CONCLUSIONS--These data suggest that resting
metabolic rate in cats decreases after gonadectomy. CLINICAL
RELEVANCE--A decrease in metabolic rate is synonymous with a decrease
in caloric requirements. Gonadectomized animals fed in a manner similar
to sexually intact animals may be predisposed to obesity and its sequelae.
VII. Infectious Disease Considerations
J. AM. Vet. Med Assoc. 2001;218(2):217-21Howe LM; Slater MR; Boothe HW;
Hobson HP; Long-term outcome of gonadectomy performed at an early
age or traditional age in dogs. Holcom JL; Spann AC, Department of Small
Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M
University, College Station 77843-4474, USA.
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OBJECTIVE: To determine long-term results and complications of
gonadectomy performed at an early age (prepubertal) or at the
traditional age in dogs. DESIGN: Cohort study. ANIMALS: 269 dogs from
animal shelters. PROCEDURE: Dogs that underwent gonadectomy were
allotted to 2 groups on the basis of estimated age at surgery (traditional
age, > or =24 weeks old; prepubertal, < 24 weeks old). Adoptive owner
information was obtained from shelter records, and telephone interviews
were conducted with owners to determine physical or behavioral
problems observed in the dogs since adoption. Follow-up information was
obtained from attending veterinarians for dogs with complex problems or
when owners were uncertain regarding the exact nature of their dog's
problem. RESULTS: Prepubertal gonadectomy did not result in an
increased incidence of behavioral problems or problems associated with
any body system, compared with traditional-age gonadectomy, during a
median follow-up period of 48 months after gonadectomy. Rate of
retention in the original adoptive household was the same for dogs that
underwent prepubertal gonadectomy as those that underwent
traditional-age gonadectomy. Infectious diseases, however, were more
common in dogs that underwent prepubertal gonadectomy.
CONCLUSIONS AND CLINICAL IMPLICATIONS: With the exception of
infectious diseases, prepubertal gonadectomy may be safely performed
in dogs without concern for increased incidence of physical or behavioral
problems during at least a 4-year period after gonadectomy.
VIII. Surgical Considerations
J Am Vet Med Assoc. 1996 Jun 1;208(11):1882-6.
Postoperative complications of elective surgeries in dogs and cats
determined by examining electronic and paper medical records. Pollari
FL, Bonnett BN, Bamsey SC, Meek AH,
Allen DG. Department of Population Medicine.
Postoperative complications (POC) that developed in dogs and cats that
underwent elective ovariohysterectomy, castration, and declaw at a
veterinary teaching hospital were determined by examining the
computerized abstracts of the medical records and by examining a
random sample of the paper medical records. When the computerized
abstracts were examined, POC were found to have occurred in 62 (6.1%)
of 1,016 dogs. One dog died and 6 others developed major
complications. Postoperative complications were found to have occurred
in 38 (2.6%) of 1,459 cats. Two cats died and 1 was euthanatized. Four
other cats developed major complications. Complete paper medical
records for 218 dogs and cats were examined. When the paper medical
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records were examined, the proportions of dogs and cats with POC were
19.4% and 12.2%, respectively. These proportions were 4 to 7 times higher
than when the computerized abstracts were the data source. Results of
this study indicate that the frequency of clinically relevant POC of elective
surgeries in dogs and cats is substantial. Examination of the computerized
abstracts of medical records at this hospital allowed us to rapidly identify
cases that could be included in the study but the frequency of POC
would be significantly underestimated if paper records were not also
assessed.
Vet Rec. 2005 Dec 24-31;157(26):829-33.
Complications observed during and after ovariohysterectomy of 142
bitches at a veterinary teaching hospital. Burrow R, Batchelor D, Cripps P.
Small Animal Hospital, Department of Veterinary Clinical Science,
University of Liverpool, Crown Street, Liverpool L7 7EX, UK.
The clinical, anaesthetic and surgical records of 142 bitches admitted into
the primary care clinic at the Small Animal Hospital, University of Liverpool,
between January 2002 and August 2004 for routine ovariohysterectomy
by final-year students were analysed for complications during and after
the surgery. The time taken to perform the surgical procedure was
recorded, to allow assessment of the time involved in one-to-one surgical
teaching during live-recovery surgeries of client-owned pets. The types of
complications were similar to those reported in earlier studies: nine bitches
suffered haemorrhage of the ovarian arteries during surgery, and there
were four cases of haemorrhage after surgery, 12 cases of wound
inflammation and four other types of complication. The rates of
intraoperative, postoperative and total complications were 6.3, 14.1 and
20.6 per cent, respectively.
Can Vet J. 2007 Feb;48(2):169-77.
Prevalence of perioperative arrhythmias in 50 young, healthy dogs.
Duerr FM, Carr AP, Duke T, Shmon CL, Monnet E.
Department of Small Animal Clinical Sciences, Western College of
Veterinary Medicine, University of Saskatchewan, Saskatoon,
Saskatchewan.
The objective of this study was to assess the type and frequency of
cardiac dysrhythmias occurring after routine ovariohysterectomy or
orchidectomy in young, healthy dogs by using 2 anesthetic protocols
(group I: propofol and isoflurane; group II: thiopental and halothane). Fifty
dogs under 2 years of age, judged to be clinically normal by physical
examination and standard electrocardiography, were evaluated by using
Compiled by Melody Farquhar-Chang 4-15-07
Veterinary Abstracts
Page 25 of 26
24-hour ambulatory electrocardiography. The most common dysrhythmias
in the postoperative period were 2nd degree atrioventricular block (44%),
ventricular premature complexes (44%), and atrial premature complexes
(32%). For study purposes, more than 100 ventricular or atrial premature
complexes per 24 hours, or any occurrence of R-on-T phenomenon,
ventricular or atrial tachycardia were classified as clinically significant
arrhythmias. Significant arrhythmias were observed in 9 dogs in the
postoperative period, 5 of which were in group I and 4 in group II. All of
these dogs were under 1 year of age. The R-on-T phenomenon occurred
in 4 dogs in group II and 1 dog in group I. Results from this study show that
significant arrhythmias, including R-on-T phenomenon, can occur in the
perioperative period in young, healthy dogs undergoing routine surgeries
with both protocols used.
Tierarztl Prax Ausg K Klientiere Heimtiere. 1997 Nov;25(6):637-42.
Pediatric and geriatric small animal patients as risk groups in anesthesia
management Kramer S. Klinik fur kleine Haustiere, Tierarztlichen
Hochschule Hannover.
In the first 12 weeks of postnatal life puppies and kittens are defined by
the term pediatric, because of their immature organ systems. In
anaesthesiology they are considered as high risk patients. Dogs and cats
can be defined by the term geriatric when they have completed 80% of
their expected life spans. These patients show age-related decline in
organ functions or in their mechanisms of compensation. Physiological
and pathophysiological characteristics of pediatric and geriatric patients
are discussed and principles of the perioperative anaesthetic
management and of pediatric and geriatric anaesthetic techniques are
given.
IX. Vaccine Considerations
J Am Vet Med Assoc. 2005 Oct 1;227(7):1102-8.
Adverse events diagnosed within three days of vaccine administration in
dogs. Moore GE, Guptill LF, Ward MP, Glickman NW, Faunt KK, Lewis HB,
Glickman LT. Department of Veterinary Pathobiology, School of
Veterinary Medicine, Purdue University, West Lafayette, IN 47907-2027,
USA.
OBJECTIVE: To determine incidence rates and potential risk factors for
vaccine-associated adverse events (VAAEs) diagnosed within 3 days of
administration in dogs. DESIGN: Retrospective cohort study. ANIMALS:
1,226,159 dogs vaccinated at 360 veterinary hospitals. PROCEDURE:
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Veterinary Abstracts
Page 26 of 26
Electronic records from January 1, 2002, through December 31, 2003, were
searched for possible VAAEs (nonspecific vaccine reaction, allergic
reaction, urticaria, or anaphylaxis) diagnosed within 3 days of vaccine
administration. Information included age, weight, sex, neuter status, and
breed. Specific clinical signs and treatments were reviewed in a random
sample of 400 affected dogs. The association between potential risk
factors and a VAAE was estimated by use of multivariate logistic
regression. RESULTS: 4,678 adverse events (38.2/10,000 dogs vaccinated)
were associated with administration of 3,439,576 doses of vaccine to
1,226,159 dogs. The VAAE rate decreased significantly as body weight
increased. Risk was 27% to 38% greater for neutered versus sexually intact
dogs and 35% to 64% greater for dogs approximately 1 to 3 years old
versus 2 to 9 months old. The risk of a VAAE significantly increased as the
number of vaccine doses administered per office visit increased; each
additional vaccine significantly increased risk of an adverse event by 27%
in dogs < or = 10 kg (22 lb) and 12% in dogs > 10 kg. CONCLUSIONS AND
CLINICAL RELEVANCE: Young adult small-breed neutered dogs that
received multiple vaccines per office visit were at greatest risk of a VAAE
within 72 hours after vaccination. These factors should be considered in
risk assessment and risk communication with clients regarding
vaccination.
Compiled by Melody Farquhar-Chang 4-15-07