Urethral Obstruction and Urolithiasis Associated with Patent Urachus in a 12-Week-old Kitten

Case summary A 12-week-old intact male domestic shorthair kitten presented for dysuria. The patient had a urethral obstruction that was relieved with urinary catheter placement. A cutaneous opening at the umbilicus was identified. Three-view abdominal radiographs and a contrast study revealed a patent urachus with no evidence of urine leakage into the abdomen. An exploratory laparotomy was performed that confirmed a patent urachus, which was excised, and cystic and urethral calculi, which were removed via cystotomy. The patient recovered well from surgery, with a 12 h period of stranguria occurring 2 days postoperatively, attributed to residual inflammation. Calculi analysis revealed struvite stones, likely secondary to infection and inflammation. At the time of writing, 3 months postoperatively, the kitten had one episode of hematuria and inappropriate urination, which resolved with a short course of non-steroidal anti-inflammatory drugs, but had been otherwise been asymptomatic and healthy. Relevance and novel information To our knowledge, this is the first report of urolithiasis and patent urachus in a pediatric feline patient. Based on the occurrence of struvite stones in the presence of a patent urachus in an animal of this age, we suspect that chronic infection and inflammation led to the development of urolithiasis. Correction of the patent urachus resulted in almost complete resolution of clinical signs and no crystal formation was appreciated on recheck urinalysis.