Neoplasia of the equine urinary bladder is seldom reported in the literature and is considered uncommon.2,7 Clinical cases are rarely described, and those reported often involve slaughterhouse studies. Of those tumors of the urinary bladder reported, most occurred in aged mares, although aged geldings were also affected. 2,7,9 Benign tumors of the urinary bladder include papillomas, adenomas, fibromas, leiomyomas, angiomas, and fibroepithelial polyps. 9,10 There are several reports of malignant tumors; however, the vast majority of cases were documented in the early 1900s.3 Squamous cell carcinoma and transitional cell carcinoma have been most frequently identified in the literature. 2,4,7 This report describes a malignant primary urinary bladder tumor in a filly.A 2-year-old Appaloosa filly was presented to the University of Missouri Veterinary Teaching Hospital with a brief history of stranguria and hematuria. A large multinodular mass protruded into the vagina through a markedly dilated urethral orifice. The mass was debulked, and representative samples were submitted to the Veterinary Medical Diagnostic Laboratory at the University of Missouri. A tentative diagnosis of botryoid rhabdomyosarcoma was made at this time, and the owners elected to take the filly home despite the poor prognosis. Approximately 3 months later, stranguria recurred and the filly was returned to the teaching hospital. Rectal palpation revealed a mass caudal to the left kidney, and the decision was made to euthanize the filly because of From the Veterinary Medical Diagnostic Laboratory (Tumquist, Pace, Kreeger, Bailey), the Veterinary Teaching Hospital (Keegan,

Correlations between observers were moderately strong or strong for 8 of 10 measurements. Specimen positioning was repeatable. The offset ratios indicate that dogs have a substantial cranial and ventral offset of the femoral head from the femoral neck.

tained at the time of bladder-washout localization. However, investigators using voided urine specimens must be aware of false-positive results from contamination with bacteria originat¬ ing from feces.3 False-positive find¬ ings can also occur if a negative control is not always studied concomitantly with the unknown. Nonspecific fluorescence can result in a falsepositive ACB test. Perhaps antibody present in the urine can attach to organisms in the bladder and give false-positive results. However, we have not observed this in our patient population.Regardless of the reasons for the disparity, further studies are needed to determine the usefulness of the ACB test in all categories of patients with urinary tract infection. At pres¬ ent, we do not think the test should be used routinely in hospital laborato¬ ries, but should be available for women in epidemiologic and thera¬ peutic studies so that the contribution of the site of infection to course of the illness may be evaluated.