Canine urolithiasis: diagnosis and treatment.

Over 97% of all uroliths in males less than a year of age and in females are phosphate, excluding males with portosystemic shunts and male Dalmatians . Uroliths in male Dalmatians usually are composed of urate. Uroliths associated with Staphylococcus aureus urinary tract infection are phosphate. About 60% of uroliths in adult male Basset Hounds , Bulldogs , Chihuahuas , Irish Terriers and Yorkshire Terriers are cystine. In males of other breeds, as high as 60% of uroliths are phosphate. Feeding a calculolytic diet (s/d: Hill's) results in phosphate urolith dissolution in 2-20 weeks. Long-term feeding of the calculolytic diet is not recommended, nor is use after surgery and in pregnant, lactating or growing dogs and in those with heart failure, edema, ascites or pleural effusions. Uroliths recur in 20-50% of affected dogs without subsequent dietary alteration. Use of a urolith-prevention diet (u/d: Hill's) is recommended if urolithiasis recurs.