RESUMO
An 8-month-old neutered male ferret was presented for vaccination and preventive treatment for adrenal gland disease. Abdominal ultrasound revealed severe bilateral hydronephrosis and hydroureter. Excretory urography and negative contrast cystography showed bilateral ureterovesical junction stenosis. Positive retrograde cystography demonstrated right ureteral reflux. A subcutaneous ureteral bypass was placed in the left kidney; however, it had to be removed 3 months later due to an obstruction and persistent urinary tract infection. Bilateral ureteroneocystotomy was performed. Although congenital strictures are uncommon in veterinary patients, they should be included in the differential diagnosis in ferrets presenting with hydronephrosis and hydroureter of undetermined cause.