Recurrence of canine urolithiasis.

A retrospective analysis of urolithiasis in the dog was done at the Animal Medical Center, New York, NY, and involved a review of case records from Jan 1, 1968, to June 30, 1974. The study involved a total of 438 dogs that had a total of 561 urolithic episodes. Of the 438 dogs, 111 had 155 known recurrences of calculi. The types of recurrent calculi were phosphate (54 dogs), cystine (45 dogs), urate (7 dogs), oxalate (3 dogs), and carbonate (2 dogs). Two-thirds of the recurrent cases involved only 2 episodes. One-half of the population was composed of mixed breeds, Schnauzers, and Poodles. With the exception of 25 females that had phosphate calculi, all of the dogs with recurrences were males. Sixty-six dogs were tested for urinary bacteria and of these dogs, 40 had infected urinary tracts. The infected dogs had both phosphate and cystine calculi. In addition, most dogs with phosphate calculi had Staphylococcus infections, whereas the cultures from the dogs with cystine calculi had a wide range of bacteria.