Feline insular amyloid: incidence in adult cats with no clinicopathologic evidence of overt diabetes mellitus.

Pancreatic tissues from 93 adult domestic cats with no clinicopathologic evidence of overt diabetes mellitus were examined for islet amyloid. Amyloid deposits were found in the pancreatic islets of 44 cats. Approximately one-third of these deposits were not seen with HE, but subsequently were identified with Congo red stain. The proportion of islets with amyloid, the intra-islet location of amyloid, and the amount of amyloid in individual islets also were characterized. In this select population of adult cats, the presence or absence of islet amyloid was not linked significantly (p = greater than 0.05) to age, breed, sex or primary anatomic diagnosis. Results of this study indicate that: the incidence of islet amyloid in cats is higher than previously recognized; as in man, islet amyloid can occur in cats without concurrent overt diabetes mellitus; and islet amyloid should not be considered pathognomonic for diabetes mellitus.