Diabetes mellitus in a red-tailed hawk (Buteo jamaicensis).

An adult, free-living female red-tailed hawk (Buteo jamaicensis) with clinical signs of generalized weakness, polyuria, and polydipsia, was killed and necropsied. An ante mortem serum sample taken from the bird contained 54.3 mmole/1 glucose, and large amounts of glucose were found in the urine. At necropsy, the pancreas was small, pale pink with multiple, round, approximately 0.5 mm white foci. Light and electron microscopic examination of the pancreas revealed markedly vacuolated islet cells. Histochemical examination of the tissue showed that the vacuolated cells were beta-cells. This is the first report of spontaneously occurring diabetes mellitus in a raptor.