Cystine calculi I in the dog: an epidemiological retrospective study

During 1970 to 1990, 134 cases of obstructive cystine calculi were diagnosed in Sweden; it was estimated that at least two out of 10,000 male dogs in Sweden had this condition. The disease was found especially in the dachshund, basset hound and Welsh corgi (0–2 to 04 per cent). The study showed that obstructive cystine calculi occur in male dogs of all ages, but not in females or pups. Most cases (53 per cent) were detected at the age of three to five years. Recurrence was common (38 per cent), but was rare in older dogs. Eight dogs which originally had cystine calculi suffered recurrent stones consisting of magnesium ammonium phosphate. Surgery was performed in 40 per cent for the first time (n=122) during the first quarter of the year and in 71 per cent during January to July. Since this condition affects only male dogs after sexual maturity, it was assumed that the formation of cystine calculi involved the sex hormone(s).