LAUSR

Abstract A 6-year-old, 1.9-kg female spayed lop-eared European rabbit ( Oryctolagus cuniculus ) was evaluated for acute hematuria and inappropriate urination and defecation of less than 12-hours duration. Abdominal ultrasonography revealed a suspected bladder mass. Ultrasound-guided cystocentesis was performed and the results of the urinalysis were unremarkable. An abdominal exploratory surgery revealed a nodular cystic mass at the cranial ventral apex of the bladder wall which measured 0.5cm x 0.5cm. Based on histopathologic evaluation, excision of the neoplasm was complete and the mass was diagnosed as transitional cell carcinoma (TCC) of the bladder. This case suggests that urinary bladder TCC should be considered in pet rabbits presenting with similar clinical signs.