Feline urate urolithiasis.

This retrospective case control study describes associations between feline urate urolithiasis and breed, age, gender, and urine composition. Data from cases of feline uroliths submitted to the Canadian Veterinary Urolith Centre (CVUC) between February 2, 1998 and July 7, 2007 were reviewed. There were 10 083 feline uroliths examined, including 385 ammonium urate, 13 uric acid, and 21 mixed struvite/urate uroliths. The Egyptian Mau, Birman, and Siamese breeds were significantly predisposed to urate urolithiasis [odds ratio (OR) = 118, 95% confidence interval (CI) = 38.2 to 510, P < 0.001], (OR = 9.1, 95% CI = 2.0 to 32, P < 0.001) and (OR = 3.9, 95% CI = 2.5 to 5.9, P < 0.001), respectively. Urate urolithiasis was more frequent in younger cats (mean age 6.3 versus 7.1 y in cats with other uroliths, P < 0.0001) and in male cats (P = 0.024). The association between Egyptian Maus and urate urolithiasis was remarkable. The association in Siamese cats is consistent with prior reports, and the association with Birman cats requires further study.