Comparison of long-term effects of ovariectomy versus ovariohysterectomy in bitches. Okkens AC; Kooistra HS; Nickel RF Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands. J Reprod Fertil Suppl 1997;51:227-31 Although ovariectomy is less invasive and less time-consuming than ovariohysterectomy, most surgical textbooks recommend ovariohysterectomy for routine neutering of bitches. This advice is probably based on concerns about the development of uterine disease after ovariectomy. However, there is no evidence that conditions such as cystic endometrial hyperplasia (CEH)-endometritis develop in the ovariectomized bitch, unless progestagens are administered. The purpose of this study was therefore to compare the long-term effects of ovariectomy and ovariohysterectomy, including the incidence of urinary incontinence. Questionnaires were sent to 264 owners of bitches, in which ovariectomy (126) or ovariohysterectomy (138) had been performed as a routine neutering procedure 8-11 years earlier. Complete data were available for 69 bitches of the ovariectomy group and for 66 bitches from the ovariohysterectomy group. There were no indications that endometritis had developed in bitches of the ovariectomy group. None of the bitches was sexually attractive to male dogs after neutering. The occurrence of a clear to white vaginal discharge was reported in two bitches of each group, but none of these four bitches appeared to be ill during the periods when the discharge was present. Furthermore, with the exception of urinary incontinence, no problems were reported that could be related to the surgical neutering. Six of the ovariectomized bitches and nine of the ovariohysterectomized bitches eventually developed urinary incontinence. Of these 15 bitches (11%), 12 weighed more than 20 kg. Bouvier des Flandres bitches were at a higher risk of developing urinary incontinence than were those of the other breeds. The possibility that the urinary incontinence was due at least in part to other conditions must be considered, since eight of the bitches were 9 years or older before urinary incontinence occurred and seven of the incontinent bitches also had polyuria or polydipsia. There were no significant differences in the incidence of urogenital problems listed above between the bitches of the ovariectomy and ovariohysterectomy group. It is hypothesized that a uterine disease such as CEH-endometritis cannot develop after complete ovariectomy, unless progestagens are administered. The results of this study indicate that ovariectomy does not increase the risk of CEH-endometritis or other complications in comparison with ovariohysterectomy. It is concluded that there is no indication for removing the uterus during routine neutering in healthy bitches. On the contrary, ovariectomy should be considered the procedure of choice. Longevity of British breeds of dog and its relationships with sex, size, cardiovascular variables and disease. Michell AR Centre for Small Animal Studies, Animal Health Trust, Newmarket, Suffolk. Vet Rec 1999 Nov 27;145(22):625-9 Neutered females lived longer than males or intact females, but among dogs dying of natural causes entire females lived slightly longer. In neutered males the importance of cancer as a cause of death was similar to heart disease. Variation in age at death of dogs of different sexes and breeds. Bronson RT Am J Vet Res 1982 Nov;43(11):2057-9 A retrospective study of necropsy data for 2,002 dogs showed that the mean age at death of neutered dogs of both sexes exceeded that of intact dogs, but the differences were not significant. Cardiac tumors in dogs: 1982-1995. Ware WA; Hopper DL Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011-1250, USA. J Vet Intern Med 1999 Mar-Apr;13(2):95-103 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 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. Epidemiologic, clinical, pathologic, and prognostic characteristics of splenic hemangiosarcoma and splenic hematoma in dogs: 217 cases (1985). Prymak C; McKee LJ; Goldschmidt MH; Glickman LT Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6010. J Am Vet Med Assoc 1988 Sep 15;193(6):706-12 Compared with sexually intact females, only spayed females were at significantly (odds ratio [or], 2.2; 95% confidence interval [CI], 1.2 to 4.1) increased risk for developing SHS; sex predisposition was not found for dogs with SHA Host related risk factors for canine osteosarcoma. Ru G; Terracini B; Glickman LT Department of Animal Pathology, University of Turin, Italy. cea@to.iZS.it Vet J 1998 Jul;156(1):31-9 A twofold excess risk was observed among neutered dogs. Vulvar and vaginal tumors in the dog: a retrospective study. Thacher C; Bradley RL J Am Vet Med Assoc 1983 Sep 15;183(6):690-2 Most of the dogs were old (average age, 10.8 years) and sexually intact. Of the 99 tumors, 72 were benign, 17 were malignant, and 10 were transmissible venereal tumors. Except for the transmissible venereal tumors, most tumors were of smooth muscle or fibrous tissue origin (leiomyoma, fibroma, and leiomyosarcoma). In the dogs with benign tumors, surgical excision of the tumor combined with ovariohysterectomy was effective in preventing recurrence of disease. Factors influencing the incidence and prognosis of canine mammary tumours [In Process Citation] Perez Alenza MD; Pena L; del Castillo N; Nieto AI Department of Animal Pathology II, Veterinary School, Complutense University, Madrid, Spain. J Small Anim Pract 2000 Jul;41(7):287-91 Increased age, intact status or ovariectomy after 2.5 years of age, as well as progestagen treatment, can all lead to an increased risk of mammary neoplasia in the bitch. In addition, obesity early in life, and a habitual diet based on home-made food (rich in beef and pork, and poor in chicken) as opposed to commercial food, are also associated with the occurrence of mammary tumours. Body conformation, diet, and risk of breast cancer in pet dogs: a case-control study. Sonnenschein EG; Glickman LT; Goldschmidt MH; McKee LJ Department of Environmental Medicine, New York University Medical School, NY 10010. Am J Epidemiol 1991 Apr 1;133(7):694-703 The risk of breast cancer was significantly reduced in dogs spayed at or before 2.5 years of age. Neither a high-fat diet nor obesity 1 year before diagnosis increased the risk of breast cancer according to multiple logistic regression analysis. However, the risk of breast cancer among spayed dogs was significantly reduced in dogs that had been thin at 9-12 months of age (odds ratio (OR) = 0.04 (95% confidence interval (CI) 0.004-0.4) and OR = 0.04 (95% CI 0.004-0.5) for cases vs. cancer controls and cases vs. noncancer controls, respectively, after adjustment for age at spay). Among intact dogs, the risk associated with being thin at 9-12 months of age was reduced, but not significantly so (OR = 0.60 (95% CI 0.2-1.9) and OR = 0.51 (95% CI 0.2-1.4) for the two comparisons, respectively). Results of this study suggest that nutritional factors operating early in life may be of etiologic importance in canine breast cancer. Effect of spaying and timing of spaying on survival of dogs with mammary carcinoma. Sorenmo KU; Shofer FS; Goldschmidt MH Department of Clinical Studies and Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6010, USA. karins@vet.upenn.edu J Vet Intern Med 2000 May-Jun;14(3):266-70 Signalment, spay status and spay age, tumor characteristics, treatment. survival, and cause of death of 137 dogs with mammary gland carcinoma were analyzed. The dogs were classified into 3 groups according to spay status and spay time: intact dogs, dogs spayed less than 2 years before tumor surgery (SPAY 1), and dogs spayed more than 2 years before their tumor surgery (SPAY 2). Dogs in the SPAY 1 group lived significantly longer than dogs in SPAY 2 and intact dogs (median survival of 755 days, versus 301 and 286 days, respectively, P = .02 and .03). After adjusting for differences between the spay groups with regard to age, histologic differentiation, and vascular invasion, SPAY 1 dogs survived 45% longer compared to dogs that were either intact or in the SPAY 2 group (RR = .55; 95% CI .32-.93; P = .03). This study reveals ovariohysterectomy to be an effective adjunct to tumor removal in dogs with mammary gland carcinoma and that the timing of ovariohysterectomy is important in influencing survival. 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 University of Guelph Ontario, Canada. J Vet Intern Med 1992 May-Jun;6(3):145-53 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. Neutered dogs were predisposed as were Airedale Terriers, Beagles, and Scottish Terriers Frequency of canine and feline tumors in a defined population. MacVean DW; Monlux AW; Anderson PS Jr; Silberg SL; Roszel JF Vet Pathol 1978 Nov;15(6):700-15 The Tulsa Registry of Canine and Feline Neoplasms was the second animal tumor registry in the United States concerned with a defined population in a delimited geographic area. Only tumors histologically confirmed by registry pathologists were included in frequency statistics based on the annual dog and cat population presented to veterinarians. During the first registry year, about 1% of the 63,504 dogs and 0.5% of the 11,909 cats had one or more primary tumors. While the incidence rate for malignant tumors in dogs was similar to that in cats, the incidence of benign tumors of dogs was over 10 times that of cats. The most common tumors were sebaceous adenoma in dogs and lymphosarcoma in cats. Mammary cancer was the most common malignant tumor in dogs. Mammary tumors of female dogs were significantly more frequent in Pointers, Poodles and Boston Terriers, in that order, than in other breeds. A greater incidence of mammary tumors among intact compared to spayed female dogs was seen for virtually every age group except in the Pointer breed. Hypothyroidism: Hypothyroidism in dogs: 66 cases (1987-1992). Panciera DL Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706. J Am Vet Med Assoc 1994 Mar 1;204(5):761-7 Neutering was determined to be the most significant gender-associated risk factor for development of hypothyroidism. Neutered male and spayed female dogs had a higher relative risk of developing hypothyroidism than did sexually intact females. Sexually intact females had a lower relative risk. Epidemiologic features of canine hypothyroidism. Milne KL; Hayes HM Jr Cornell Vet 1981 Jan;71(1):3-14 Spayed female dogs displayed a significantly higher risk when compared to intact females. Though not statistically significant, male castrated dogs had 30% more hypothyroidism compared to their intact counterparts Hypothyroidism in dogs: 66 cases (1987-1992). Panciera DL Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706. J Am Vet Med Assoc 1994 Mar 1;204(5):761-7 Sixty-six dogs with hypothyroidism were identified from dogs examined over a Neutering was determined to be the most significant gender-associated risk factor for development of hypothyroidism. Neutered male and spayed female dogs had a higher relative risk of developing hypothyroidism than did sexually intact females. Sexually intact females had a lower relative risk. Breeds with a significantly increased risk, compared with other breeds, were Epidemiologic features of canine hypothyroidism. Milne KL; Hayes HM Jr Cornell Vet 1981 Jan;71(1):3-14 Spayed female dogs displayed a significantly higher risk when compared to intact females. Though not statistically significant, male castrated dogs had 30% more hypothyroidism compared to their intact counterparts. Evaluation of risk factors for fatal acute pancreatitis in dogs. Hess RS; Kass PH; Shofer FS; Van Winkle TJ; Washabau RJ : Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6010, USA. J Am Vet Med Assoc 1999 Jan 1;214(1):46-51 Males and neutered females appeared to have an increased risk of developing fatal acute pancreatitis, compared with sexually intact females. Risk factors associated with acute pancreatitis in dogs: 101 cases (1985-1990). Cook AK; Breitschwerdt EB; Levine JF; Bunch SE; Linn LO Department of Companion Animal and Special Species Medicine, College of Veterinary Medicine, North Carolina State University, Raleigh 27606. J Am Vet Med Assoc 1993 Sep 1;203(5):673-9 Spayed dogs and castrated male dogs had an increased risk, compared with that of sexually intact males. Urinary incontinence Influence of ovariectomy on the canine striated external urethral sphincter (M. urethralis): a stereological analysis of slow and fast twitch fibres. Augsburger HR; Cruz-Orive LM Institute of Veterinary Anatomy, University of Zurich, Switzerland. Urol Res 1998;26(6):417-22 The ovariectomized dogs exhibited a statistically significant lower type I and II fibre number and a concomitant slightly larger mean single profile area (diameter) of fibre type II compared with the control animals. The significantly reduced number and decreased total cross-sectional area of the fatigue-resistant type I fibres in ovariectomized dogs suggest a predominant weakening of the fibre type I portion of the M. urethralis as consequence of ovariectomy. The effect could be mediated by sex hormonal factors and may contribute to the development of postspaying urinary incontinence in female dogs Acquired urinary incontinence in bitches: its incidence and relationship to neutering practices. Thrusfield MV; Holt PE; Muirhead RH Department of Veterinary Clinical Studies, University of Edinburgh, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Roslin, Midlothian. J Small Anim Pract 1998 Dec;39(12):559-66 The estimated incidence rates in neutered and entire animals were 0.0174 and 0.0022 per animal-year, respectively (95 per cent confidence intervals: 0.0110, 0.0275 and 0.0009, 0.0058, respectively). The relative risk, neutered vs entire, was 7.8 (95 per cent confidence interval: 2.6, 31.5). The attributable proportion(exposed) and population attributable proportion were 87.1 per cent and 63.1 per cent (95 per cent confidence intervals: 61.9 per cent, 95.6 per cent, and 28.3 percent, 88.5 per cent, respectively). An increased risk, significant at the conventional 5 per cent level, was not demonstrated in animals neutered before, vs after, first heat (relative risk: 3.9, 95 per cent confidence interval: 0.8, 10.4), although the result was significant at the 10 per cent level. Removal of the cervix was not shown to be a risk factor in neutered dogs. Acquired urinary incontinence in bitches: its incidence and relationship to neutering practices. Thrusfield MV; Holt PE; Muirhead RH Department of Veterinary Clinical Studies, University of Edinburgh, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Roslin, Midlothian. J Small Anim Pract 1998 Dec;39(12):559-66 A five-year cohort study was conducted on bitches chosen by a sample of 233 randomly selected practising veterinary surgeons in the UK, to estimate the incidence of acquired urinary incontinence (AUI) in neutered and entire animals, and to investigate possible risk factors associated with neutering practices. Information was collected using questionnaires, and data on 809 bitches, of which 22 developed AUI, were obtained. The estimated incidence rates in neutered and entire animals were 0.0174 and 0.0022 per animal-year, respectively (95 per cent confidence intervals: 0.0110, 0.0275 and 0.0009, 0.0058, respectively). The relative risk, neutered vs entire, was 7.8 (95 per cent confidence interval: 2.6, 31.5). The attributable proportion(exposed) and population attributable proportion were 87.1 per cent and 63.1 per cent (95 per cent confidence intervals: 61.9 per cent, 95.6 per cent, and 28.3 percent, 88.5 per cent, respectively). An increased risk, significant at the conventional 5 per cent level, was not demonstrated in animals neutered before, vs after, first heat (relative risk: 3.9, 95 per cent confidence interval: 0.8, 10.4), although the result was significant at the 10 per cent level. Removal of the cervix was not shown to be a risk factor in neutered dogs. Evaluation of the morphologic characteristics and prevalence of canine urocystoliths from a regional urolith center. Weichselbaum RC; Feeney DA; Jessen CR; Osborne CA; Koehler L; Ulrich L Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Veterinary Teaching Hospital, St Paul 55108, USA. Am J Vet Res 1998 Apr;59(4):379-87 About 94% of urocystoliths produced in females or spayed females were MAP, whereas males and neutered males produced a greater assortment. Prevalence of prostatic cysts in adult, large-breed dogs. Black GM; Ling GV; Nyland TG; Baker T Veterinary Medical Teaching Hospital, Davis, California, USA. J Am Anim Hosp Assoc 1998 Mar-Apr;34(2):177-80 Results of this study indicate that the prevalence of prostatic cysts in adult, intact male dogs is approximately 14% and that approximately 42% are infected with bacteria. [Urinary incontinence in castrated bitches. Part 1: Significance, clinical aspects and etiopathogenesis] Harninkontinenz bei kastrierten Hundinnen. Teil 1: Bedeutung, Klinik und Atiopathogenese. Arnold S Departement fur Fortpflanzungskunde, Veterinar-Medizinische Fakultat, Universitat Zurich. Schweiz Arch Tierheilkd 1997;139(6):271-6 Acquired urinary incontinence occurs in 20% of spayed dogs and there exists High grade prostatic intraepithelial neoplasia in military working dogs with and without prostate cancer. Aquilina JW; McKinney L; Pacelli A; Richman LK; Waters DJ; Thompson I; Burghardt WF Jr; Bostwick DG Mayo Clinic, Rochester, Minnesota 55905, USA. Prostate 1998 Aug 1;36(3):189-93 High grade PIN was identified in 3% of dogs (6 of 199 dogs) without prostate cancer. A total of 50.8% of dogs in this study group (101 of 199 dogs) were known to be sexually intact, 26.7% of dogs (53 of 199 dogs) were castrated, and the status of the remaining 22.6% of dogs (45 of 199 dogs) was unknown. High grade PIN was present in 18 of 25 dogs (72%) with prostatic adenocarcinoma. Of these cases, 11 dogs (44%) were castrated, 4 dogs (16%) were intact, and the status of 10 dogs (40%) dogs was unknown. Gleason scores ranged from 6 to 10, with a mean of 8.4 and a median of 8 Prostatic intraepithelial neoplasia occurs spontaneously in the canine prostate. Waters DJ; Bostwick DG Cancer Biology Laboratory, Purdue University, West Lafayette, Indiana 47907, USA. J Urol 1997 Feb;157(2):713-6 These results indicate that high grade PIN is frequently present in the prostate of elderly, sexually intact dogs. The prevalence of canine PIN, like human PIN, is apparently influenced by age and testicular androgens. Prostatic disorders in the dog. Johnston SD; Kamolpatana K; Root-Kustritz MV; Johnston GR College of Veterinary Medicine, Western University of Health Sciences, Pomona, CA 91766-1854, USA. sjohnston@westernu.edu Anim Reprod Sci 2000 Jul 2;60-61:405-15 Two studies suggest that risk of prostatic adenocarcinoma is increased in neutered, compared to intact male dogs. Although canine prostatic neoplasia, unlike human prostatic neoplasia, usually does not respond to androgen deprivation, recent reports of prostatic intraepithelial neoplasia (PIN) in a high percentage of older male dogs, with and without prostatic adenocarcinoma, suggests that PIN may be a precursor to adenocarcinoma in the dog as it is believed to be in man. Clinical and pathologic features of prostatic adenocarcinoma in sexually intact and castrated dogs: 31 cases (1970-1987). Bell FW; Klausner JS; Hayden DW; Feeney DA; Johnston SD Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul 55108. J Am Vet Med Assoc 1991 Dec 1;199(11):1623-30 The only significant difference between sexually intact and castrated dogs was increased prevalence of pulmonary metastasis in castrated dogs. Clinical and pathologic aspects of spontaneous canine prostate carcinoma: A retrospective analysis of 76 cases [In Process Citation] Cornell KK; Bostwick DG; Cooley DM; Hall G; Harvey HJ; Hendrick MJ; Pauli BU; Render JA; Stoica G; Sweet DC; Waters DJ Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, Indiana. Prostate 2000 Oct 1;45(2):173-83 The vast majority of canine prostate carcinomas affected elderly sexually intact dogs or dogs that underwent surgical castration after sexual maturity. High-grade prostatic intraepithelial neoplasia in dogs. Waters DJ Cancer Biology Laboratory, School of Veterinary Medicine, Purdue University, West Lafayette, Ind. 47907, USA. Eur Urol 1999;35(5-6):456-8 In another study, we showed that HGPIN is present in the majority (55%) of elderly sexually intact pet dogs without clinical evidence of prostate cancer. We are also testing the potential utility of pet dogs for the rapid, cost-effective in vivo screening of chemopreventive agents by using the prevalence and extent of HGPIN in the dog prostate as a surrogate endpoint biomarker Clinical and pathologic aspects of spontaneous canine prostate carcinoma: A retrospective analysis of 76 cases [In Process Citation] Cornell KK; Bostwick DG; Cooley DM; Hall G; Harvey HJ; Hendrick MJ; Pauli BU; Render JA; Stoica G; Sweet DC; Waters DJ Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, Indiana. Prostate 2000 Oct 1;45(2):173-83 The vast majority of canine prostate carcinomas affected elderly sexually intact dogs or dogs that underwent surgical castration after sexual maturity. Orthopedics Breed, sex, and body weight as risk factors for rupture of the cranial cruciate ligament in young dogs. Duval JM; Budsberg SC; Flo GL; Sammarco JL Department of Small Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602, USA. J Am Vet Med Assoc 1999 Sep 15;215(6):811-4 Increased risk was detected for neutered males and neutered females, compared with sexually intact males and sexually intact females, respectively. Differences in prevalence of rupture of the CCL were not detected between all males and females, sexually intact males and sexually intact females, or neutered males and neutered females. Body weights of dogs with ruptured CCL were significantly greater than those of control dogs. 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. J Am Vet Med Assoc 1993 Oct 1;203(7):1016-9 Data from 10,769 dogs with rupture of the cranial cruciate ligament (CCL) 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 : Breed, sex, and body weight as risk factors for rupture of the cranial cruciate ligament in young dogs. Duval JM; Budsberg SC; Flo GL; Sammarco JL Department of Small Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602, USA. J Am Vet Med Assoc 1999 Sep 15;215(6):811-4 Increased risk was detected for neutered males and neutered females, compared with sexually intact males and sexually intact females, respectively. Differences in prevalence of rupture of the CCL were not detected between all males and females, sexually intact males and sexually intact females, or neutered males and neutered females. Study of obesity in dogs visiting veterinary practices in the United Kingdom. Edney AT; Smith PM Vet Rec 1986 Apr 5;118(14):391-6 Neutered females were about twice as likely to be obese as entire females. The same trend was evident with neutered males. Use of a microtiter Coombs' test for study of age, gender, and breed distributions in immunohemolytic anemia of the dog. Jacobs RM; Murtaugh RJ; Crocker DB J Am Vet Med Assoc 1984 Jul 1;185(1):66-9 When age and gender were considered together, females were 4.3 times more likely to have immunohemolytic anemia than were males (P less than 0.05). When corrected for population age distribution, spayed females were not predisposed to the problem. Comparison of age- and sex-specific incidence rate patterns of the leukemia complex in the cat and the dog. Schneider R J Natl Cancer Inst 1983 May;70(5):971-7 In the dog, the neutered male was at lowest risk while the other three sex categories were clustered. However, the magnitude of expression within each species separately was the same for the neutered male, entire male, and entire female, but not for the neutered female. Neutering decreased the risk of leukemias in the female cat by approximately one-half but did not affect the risk of leukemias in the female dog. Epizootiologic patterns of diabetes mellitus in dogs. Marmor M; Willeberg P; Glickman LT; Priester WA; Cypess RH; Hurvitz AI Am J Vet Res 1982 Mar;43(3):465-70 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 Diabetic cataracts: different incidence between dogs and cats. Salgado D; Reusch C; Spiess B Veterinar-Chirurgische Klinik, Universitat Zurich. Schweiz Arch Tierheilkd 2000 Jun;142(6):349-53 the groups with the highest frequency of presentation were females and sexually intact animals Evaluation of risk factors for blastomycosis in dogs: 857 cases (1980-1990) [published erratum appears in J Am Vet Med Assoc 1993 Mar 1;202(5):775] Rudmann DG; Coolman BR; Perez CM; Glickman LT Department of Veterinary Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907. J Am Vet Med Assoc 1992 Dec 1;201(11):1754-9 Generally, the highest-risk group was composed of sexually intact male dogs, 2 to 4 years old, weighing 22.7 to 34.1 kg. This same pattern was Risk factors for relinquishment of dogs to an animal shelter. Patronek GJ; Glickman LT; Beck AM; McCabe GP; Ecker C Department of Veterinary Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA. J Am Vet Med Assoc 1996 Aug 1;209(3):572-81 OBJECTIVE--To identify canine and household characteristics associated with relinquishment of a pet dog to an animal shelter. DESIGN--Case-control study. SAMPLE POPULATION--Households that relinquished dogs for adoption (case households) and a random sample of current dog-owning households in the same community (control households). RESULTS--Potentially modifiable factors that explained the highest proportion of relinquishment were owners not participating in dog obedience classes after acquisition, lack of veterinary care, owning a sexually intact dog, inappropriate care expectations, and dogs having daily or weekly inappropriate elimination. Dogs obtained from shelters, kept in crates, or acquired at > or = 6 months of age were at increased risk of relinquishment. Greater purchase price was associated with decreased risk of relinquishment, but relinquishment was not associated with the degree of planning to acquire the dog. Dogs with behavioral problems and little veterinary care were at greater risk of relinquishment than were dogs with regular veterinary care, and behavioral problems were associated with inappropriate care expectations. Risk factors associated with parvovirus enteritis in dogs: 283 cases (1982-1991). Houston DM; Ribble CS; Head LL Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada. J Am Vet Med Assoc 1996 Feb 15;208(4):542-6 Risk factors for development of chronic superficial keratitis in dogs. Chavkin MJ; Roberts SM; Salman MD; Severin GA; Scholten NJ Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523. J Am Vet Med Assoc 1994 May 15;204(10):1630-4 Among dogs < 4 years old, spayed females, sexually intact males, and castrated males were more likely to develop the condition (P < 0.05) than were sexually intact females. Risk factors for acquired myasthenia gravis in dogs: 1,154 cases (1991-1995). Shelton GD; Schule A; Kass PH Department of Pathology, School of Medicine, University of California-San Diego, La Jolla 92093-0612, USA. J Am Vet Med Assoc 1997 Dec 1;211(11):1428-31 OBJECTIVE: To determine frequency of initial clinical signs and risk factors for acquired myasthenia gravis (MG) in dogs. DESIGN: Retrospective study. Sexually intact males and dogs less than 1 year old had some protection from risk. A retrospective case-control of acute renal failure in 99 dogs. Vaden SL; Levine J; Breitschwerdt EB Department of Companion Animal and Special Species Medicine, North Carolina State University, College of Veterinary Medicine, Raleigh 27606, J Vet Intern Med 1997 Mar-Apr;11(2):58-64 PMID: 9127291 UI: 97272585 Intact male dogs and nonsporting dogs were more likely to develop ARF and be admitted to the teaching hospital Risk factors associated with canine heartworm infection. Selby LA; Corwin RM; Hayes HM Jr J Am Vet Med Assoc 1980 Jan 1;176(1):33-5 Intact male dogs 4 to 7 years old and of the larger hound breeds had the highest relative risk, whereas dogs of smaller breeds, those less than 2 years old, spayed females, and castrated males were at least risk.