A bitch two and half year old, weighting 5 kg with complaints of frequent tenesmus and difficult, dripling and haemorrhagic urination was admitted to the Surgery Clinic of the Veterinary Faculty. The external physical examination of the abdominal wall, revealed the presence of a hard regular object in the caudal part of abdomen, likely in the urinary bladder. At the same time direct radiological examination in the lateral position was performed and revealed regular object shape of guadrangle.

For the premedication Xylazine hydrochloride (Rompun) 2 mgr/kg body weight i.m. and Ketamine HCL (Ketalar, 50 mgrjml) 20 mg/kg body weight i.m. for the general anaesthesia were administred. Calculi vesicalis was removed by laparo-cystotomy. The bladder was lavaged with penicillin and saline solution. But the dog was died postoperative period due to uremie. Necropsy revealed hydronephros and chronic cystitis.

Calculi vesicalis was found 99.610 gr. weight. Dimensions of the calculi were 5.5x4.5x3.8 cm. Biochemical analysis of calculi vesicalis was made in the Biochemistry Laboratory in the Medical School and reported that the composition was Phosphate in nature.

This case has been reported because of that big size of calculi vesicalis wasn't seen until now in our clinic.