Congenital bilateral renal dysplasia in a Cavalier King Charles Spaniel

This report describes a case of congenital bilateral renal dysplasia in a Cavalier King Charles Spaniel (CKCS) puppy, which has not been previously reported in the breed. An 8‐week‐old male intact CKCS was presented to a University Teaching Hospital for the evaluation of vomiting and lab work revealed azotemia. The puppy was treated with medical management involving fluid therapy, antibiotics, and supportive care. Due to the development of unresponsive oliguric renal failure, puppy's level of care intensified and peritoneal dialysis was initiated and continued over a 12‐day course. After initiating peritoneal dialysis, azotemia improved but the patient acutely declined after an episode of regurgitation and ultimately cardiopulmonary arrest. Postmortem examination revealed bilateral persistent fetal glomeruli, tubular dysplasia, and rare tubular necrosis. While congenital renal dysplasia has been reported in other canine breeds, to the authors’ knowledge, this is the first report of congenital renal dysplasia in a CKCS.