Two siblings, a 6-month-old sexually intact male weighing 2.5 kg (cat 1) and a sexually intact female (cat 2) British shorthair cat weighing 2.3 kg, were examined because of a 3-week history of polyuria, lethargy and laboured breathing. One year previously, another sibling (cat 3) had been presented because of similar, yet more severe, clinical signs at the age of 5 months. Physical examination revealed lethargy, dehydration and polypnoea with slightly increased inspiratory effort. Diagnostic investigation revealed severe hypercalcaemia (cats 1-3), renal azotaemia (cats 1 and 3) and a radiologically generalised miliary interstitial pattern of the lungs (cats 1-3) attributable to hypervitaminosis D caused by ingestion of commercial cat food. Cat 3 was euthanased. Cats 1 and 2 were treated with isotonic saline solution (180 ml/kg IV daily), sucralfate (30 mg/kg PO q12h), terbutaline (only cat 1: 0.1 mg/kg SC q4h), furosemide (1.5 mg/kg IV q8h) and tapering doses of prednisolone. Cat 2 was normal on day 14. Cat 1 had stable renal disease and was followed up to day 672. The radiological generalised miliary interstitial pattern of the lungs had improved markedly. Excessive cholecalciferol-containing commercially available cat food poses a great hazard to cats. Supportive treatment may result in long-term survival and improvement of radiological pulmonary abnormalities. The study is from the Ludwig Maximilian University, Clinic of Small Animal Medicine, Munich, Germany.
Wehner A, Katzenberger J, Groth A, et al. J Feline Med Surg 2013 Jan 7 [Epub ahead of print].