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Summary

A computer-based search was conducted of medical and necropsy records of horses admitted to the teaching hospital from Jan 1, 1979, to Dec 31, 1987, to obtain the records of all horses admitted to the hospital for colic and subsequently found to have gastric rupture. Fifty cases of gastric rupture were found. The records were reviewed to obtain data regarding peritoneal fluid analysis. Cell counts of these samples were often erroneous because debris and clumps of bacteria were counted when most WBC were lysed.

A cross-sectional study of gastric rupture cases versus all other colic cases regarding season of admission revealed that there was no association between season and the occurrence of gastric rupture. There was also no increased risk associated with age, gender, breed, and the occurrence of gastric rupture.

One hundred colic cases, matched with the gastric rupture cases by year of admission, were randomly selected via a table of random numbers. A questionnaire regarding age, breed, gender, use of the horse, housing, diet, water source, deworming schedule, and medical history was completed from the medical records and phone conversations with the horse owners. The results indicated that horses on a diet of grass hay or grass/alfalfa hay only or those that drank water from a bucket, stream, or pond were at increased risk for having gastric rupture. In contrast, horses fed grain had a reduced risk.

Free access
in Journal of the American Veterinary Medical Association

Summary

Between January 1978 and December 1988, 147 horses with ocular/adnexal squamous cell carcinoma (scc) were admitted to the Colorado State University Veterinary Teaching Hospital (CSU-VTH). Diagnosis was conjirmed by histologic examination of appropriate tissue specimens. Medical records and communication with owners, referring veterinarians, or both provided information regarding initial examination, treatment at the CSU-VTH, and final outcome. At initial examination, 123 (83.7%) horses had unilateral involvement and 24 (16.3%) horses had bilateral involvement. The nictitating membrane, nasal canthus, or both (28.1%); limbus (27.5%); and eyelid (22.8%) were most commonly affected. In addition to the ocular/adnexal location, scc was found elsewhere in 14 (9.5%) horses at initial examination. Adequate follow-up (≥ 4 months) for examination of tumor recurrence and survival analysis was obtained for 125 (85.0%) cases. After treatment at the CSU-VTH, tumor recurred in 30.4% of the cases. Tumor location, multiple vs single tumors at initial diagnosis, and CSU-VTH treatment modality influenced the recurrence of tumors. Survival analysis revealed a good prognosis for horses with ocular/adnexal scc. Although undefined, a conservative estimate of the median survival time was 47 months. Six factors (treatment prior to referral, tumor location, tumor size, single or multiple tumors, treatment modality at the CSU-VTH, and recurrence or nonrecurrence) were analyzed to determine their relation with survival. Treatment prior to referral, multiple vs single tumors at initial examination, and treatment modality used at the CSU-VTH did not influence survival. Tumor location influenced survival; scc involving the eyelid or orbit was associated with the poorest prognosis. Tumor stage (maximal dimension) was inversely related with survival. One or more recurrences of scc markedly reduced the likelihood of survival.

Free access
in Journal of the American Veterinary Medical Association

Summary

Proportional hospital accession ratios for equine ocular/adnexal squamous cell carcinoma (scc) were determined for 14 colleges of veterinary medicine participating in the Veterinary Medical Data Program between January 1978 and December 1986. Comparison of the ratios with their respective geographical, physical data has shown an increased prevalence of scc with an increase in longitude, altitude, or mean annual solar radiation. In contrast, prevalence of scc increased with a decrease in latitude.

Between January 1978 and December 1988, 147 horses with ocular/adnexal scc were admitted to the Colorado State University Veterinary Teaching Hospital. Diagnosis was confirmed by histologic examination of appropriate tissue specimens. Medical records provided information regarding month and year of admission and diagnosis, age at diagnosis, breed, gender, and hair color. Comparison with a randomly selected hospital control population revealed an increased prevalence of ocular/adnexal scc with an increase in age (P < 0.001). Compared with Quarter Horses, draft breeds (Belgian, Clydesdale, and Shire) and Appaloosas had a significantly (P < 0.001) greater prevalence of ocular/adnexal scc. Sexually intact males and females were significantly (P < 0.001) less likely (5 and 2 times, respectively) to have ocular/adnexal scc when compared with castrated males. The prevalence of ocular/adnexal scc was significantly greater for all hair colors when compared with bay, brown, or black (P < 0.01).

Free access
in Journal of the American Veterinary Medical Association

Summary

Twelve resected canine gallbladders (in vitro) and the gallbladder in each of 14 dogs (in vivo) were ultrasonographically examined. Gallbladder volume was calculated from ultrasonographically measured geometric dimensions, using 4 volumetric model formulas: cone, ellipse, biplanar ellipse, and prolate ellipse. Calculated volume was compared with true gallbladder volume, as measured by water displacement. All examined models for calculation of gallbladder volume were closely associated with true gallbladder volume (P < 0.005), and all models provided accurate predictions of true gallbladder volume (r2 > 0.80). Calculated volumes can be corrected mathematically by use of the regression coefficient and constant for each model. Body weight was not significantly associated with gallbladder volume in any of the models considered. Use of ultrasonography to accurately measure gallbladder volume could be combined with synthetic cholecystokinin-stimulated gallbladder emptying to provide information about biliary function and patency in icteric animals. Such information could aid the clinical decision between surgical or medical treatment. Correction of calculated volumes would not be necessary in association with induced emptying studies, because volume change is more important than absolute volume.

Free access
in American Journal of Veterinary Research

SUMMARY

A survey of 1,965 equine colic cases was conducted from August 1985 to July 1986 at 10 equine referral centers located throughout the United States. The purpose of this study was to develop and validate a multivariable model for the need for surgery. Two-thirds of the cases were randomly selected for model development (1,336), whereas the remaining cases (629) were used only for subsequent validation of the model. If a lesion requiring surgical correction was found at either surgery or necropsy, the case for the horse was classified as surgical, otherwise the case was classified as medical. Only variables that were significant (P < 0.05) in an initial bivariable screening procedure were considered in the model development. Because of the large number of missing values in the data set, only variables for which there were < 400 missing values were considered in the multivariable analysis. A multivariable logistic regression model was constructed by use of a stepwise algorithm. The model used 640 cases and included variables: rectal findings, signs of abdominal pain, peripheral pulse strength, and abdominal sounds. The likelihood ratio for surgery was calculated for each horse in the validation data set, using the logistic regression equation. Using Bayes theorem, the posttest probability was calculated, using the likelihood ratio as the test odds and the prevalence of surgery cases (at each institution) as an estimate of the pretest odds. A Hosmer-Lemeshow goodness-of-fit χ2 statistic indicated that the model fit the validation data set poorly, as demonstrated by the large χ2 value of 26.7 (P < 0.001). However, when the expected proportion of surgical cases was compared with the observed proportion of surgical cases in each of 10 increments of risk, the model's performance appeared satisfactory.

Free access
in American Journal of Veterinary Research

SUMMARY

Flunixin meglumine has been reported to induce gastrointestinal lesions in dogs when administered at therapeutic dosages. We administered flunixin meglumine to dogs daily for 10 days to assess the effect of this drug on the gastrointestinal tract. We also evaluated the possibility of corticosteroid potentiation of gastrointestinal toxicosis by concurrent administration of prednisone to 1 group of dogs. Dogs were monitored for gastrointestinal toxicosis by means of serial endoscopic evaluation, measurement of fecal occult blood, pcv, and total solid concentration, and by physical examination. There were 3 treatment groups of 5 dogs each. Group-1 dogs were given 2.2 mg of flunixin meglumine/kg daily, in 2 divided doses im; group-2 dogs were given 4.4 mg of flunixin meglumine/kg daily, in 2 divided doses im; and group-3 dogs were given 2.2 mg of flunixin meglumine/kg daily, in 2 divided doses im plus 1.1 mg of prednisone/kg/d orally, in 2 divided doses. A fourth group of 5 dogs served as a control group.

Endoscopically visible gastric mucosal lesions developed in all treated dogs within 4 days of initiating treatment. Lesions first developed in the gastric pylorus and antrum and lesions at these sites were more severe than those observed elsewhere. Dogs treated with flunixin meglumine plus prednisone developed the earliest and most severe lesions; lesion scores in group-2 dogs were higher than those in group-1 dogs. All dogs treated had occult blood in their feces by day 5 and its presence appeared to correlate more closely with endoscopic findings than did physical examination findings or changes in values for pcv or total solids.

Deep ulcers were observed in the pylorus of most treated dogs examined at necropsy on day 10. Shallow ulcers and erosions were in the small intestine of group-2 and -3 dogs. Capillary microthrombi, associated with lesions of coagulative necrosis of superficial epithelium, were found in the colonic and small intestinal mucosa of several dogs in groups 2 and 3, and were suggestive of vascular injury.

From results of this study, it was concluded that flunixin meglumine, administered at therapeutic doses, induced early gastric mucosal injury in dogs and that concurrent administration of prednisone may have exacerbated the gastrointestinal injury induced by flunixin alone. Endoscopic evaluation and measurement of fecal occult blood appeared to be more sensitive than other methods evaluated for detection of gastrointestinal injury.

Free access
in American Journal of Veterinary Research

Summary

One hundred twenty-nine dogs with histologically confirmed malignant tumors were used in a prospective study to determine the toxicity of the new dihydroxyquinone derivative of anthracene, mitoxantrone, which was administered iv at 21-day intervals at dosages ranging from 2.5 to 5 mg/m2 body surface area. Each dog was evaluated for signs of toxicosis for 3 weeks after each dose was administered or until the dog died, whichever came first. The number of dogs in each evaluation period were as follows: 1 dose (n = 129), 2 doses (n = 82), 3 doses (n = 43), 4 doses (n = 26), 5 doses (n = 19), 6 doses (n = 9), 7 doses (n = 6), 8 doses (n = 5), 9 doses (n = 3), and 10 doses (n = 1). The most common signs of toxicosis were vomiting, diarrhea, anorexia, and sepsis secondary to myelosuppression. None of the dogs died of complications resulting from mitoxantrone treatment. Dogs with signs of toxicosis during the 21-day interval from administration of the first dose of mitoxantrone were 95 times (P = 0.003) more likely to develop signs of toxicosis during the 21-day interval from the second dose of mitoxantrone. Similarly, dogs that developed signs of toxicosis during the 21-day interval from the administration of the second dose were 34 times (P < 0.001) more likely to develop signs of toxicosis during the 21-day interval from the administration of the third dose. With each 1 mg/m2 increase in mitoxantrone, the odds of developing signs of toxicosis increased by 5.9 fold (P < 0.001). The performance status (modified Karnofsky performance scheme) of each dog was not adversely affected to a significant extent by mitoxantrone-induced toxicosis until the fifth dose (P = 0.0008). Cardiac toxicosis was not detected. Mitoxantrone was also administered iv to 4 clinically normal dogs, at a dosage of 5 mg/m2 of body surface area, a decrease in the neutrophil count was seen, with the nadir occurring on day 10 (mean ± sem: 1,159 ± 253 cells/μl; range, 480 to 1,680 cells/μl). Tumor-bearing dogs did not seem to have the same degree of myelosuppression (mean ± sem, 6,263 ± 1,230 cells/μl; range, 228 to 18,600 cells/μl).

Free access
in Journal of the American Veterinary Medical Association