Canine urolithiasis: retrospective analysis of 438 cases.

In a retrospective analysis of 438 cases of canine urolithiasis, a total of 561 urolithic episodes were found to have occurred in a 6 1/2-year period. The hospital incidence of urolithiasis during that period, defined as the proportion of dogs hospitalized with urolithiasis to the total number of dogs hospitalized, was 2.8%. The major chemical component of the calculus in 307 dogs was phosphate; in 95 dogs, cystine; in 21 dogs, urate; in 12 dogs, oxalate; and in 3 dogs, carbonate. The Miniature Schnauzer, Dachsund, Dalmatian, Pug, Bulldog, Welsh Corgi, Beagle, and Bassett Hound were breeds that had a significantly higher (P less than 0.05) incidence of calculi than did breeds of other dogs hospitalized. Predisposition for calculi, by sex, was not found. Most dogs with calculi were between 3 and 7 years old. Most calculi were radiopaque and were located in the bladder or in the bladder and urethra. Specimens for bacteriologic culture were obtained by catheterization or by swabbing of tissue at the surgical site. Of 259 specimens obtained, 181 were culture-positive. The most common organisms isolated were Staphylococcus spp, Escherichia coli, Proteus spp, Streptococcus spp, and Klebsiella spp. Most of the bacteria were sensitive to gentamicin, chloramphenicol, nitrofurantoin, cephalothin, and methanamine mandelate.