Abstract
Vitamin D toxicosis caused by commercially available cat food was examined clinically and experimentally. Four patient cats which had been primarily fed on the same dry cat food were referred for evaluation to Iwate University Veterinary Hospital. The vitamin D content of the cat food was 5, 290 IU/100g. X-ray examinations in all cases revealed mineral depositions of various sizes in the lung, trachea, stomach and small intestine. Plasma Ca concentration was more than 11 mg/dl in all cases except case 1 and plasma 25 (OH) D concentration was more than 100 ng/ml in all cases. Subsequently, plasma concentrations of Ca and 25 (OH) D in Case 1 increased to 16.0 mg/dl and 311.9 ng/ml, respectively. Cases 1 and 2 developed uremia and the other cases showed a moderate increase in plasma concentrations of BUN and creatinine. Histopathologically, systemic calcification was observed in the soft tissues of Cases 1 and 2. Four healthy cats were experimentally fed on the same commercially available cat food to determine the changes in plasma concentrations of vitamin D metabolites and minerals. The concentrations of Ca and 25 (OH) D had increased by 40 days later. These findings suggest that all patient cats may have developed vitamin D toxicosis due to eating cat food containing excessive amounts of vitamin D.
