CLINICAL-EVALUATION OF CATS WITH NONOBSTRUCTIVE URINARY-TRACT DISEASES

Objective-To identify the underlying cause of clinical signs in cats w ith nonobstructive diseases of the bladder and urethra. Design-Prospec tive case series. Sample Population-109 cats examined by the urology s ervice of The Ohio State University's veterinary teaching hospital bec ause of stranguria, hematuria, pollakiuria, or urination in inappropri ate locations. Procedure-History was obtained and a CBC, serum biochem ical analyses, serologic tests for FeLV and feline immunodeficiency vi rus, urinalysis, bacterial culture of urine, and contrast radiography or urethrocystoscopy (females only) were performed. Results-16 cats ha d cystic calculi: 8 had struvite uroliths, 7 had calcium oxalate uroli ths, and 1 had a urolith of unknown composition in conjunction with an anatomic defect. Anatomic defects, including diverticulae, urethral s trictures, and a malpositioned urethra, were identified in 12 cats. A urinary tract infection was identified in 1 cat, and neoplasia was dia gnosed in 2. One of the cats with neoplasia also had a struvite urolit h. The remaining 80 cats did not have an anatomic defect, urolith, or tumor. Ten of these cats also did not have radiographic or cystoscopic abnormalities and were presumed to have a behavioral disorder. The re maining 70 cats had radiographic or cystoscopic abnormalities, and idi opathic cystitis was diagnosed. In 14 of the cats with idiopathic cyst itis, results of a urinalysis were normal. Cats with idiopathic cystit is were significantly more likely to eat dry food exclusively (59%) th an were cats in the general population (19%). Clinical Implications-Re sults suggest that idiopathic cystitis occurs commonly in cats with st ranguria, hematuria, pollakiuria, or inappropriate elimination and is associated with consumption of dry foods. Contrast radiography or cyst oscopy is necessary for differentiating idiopathic cystitis from behav ioral disorders in some cats.