Diabetes in Cats

Prevalence of diabetes mellitus (DM), a common endocrinopathy in cats, is increasing. This study sought to determine population-based information about DM in cats. 

Swedish insurance records from 2009 to 2013 from a single insurance company were reviewed; age, breed, and sex of affected cats were analyzed. During this time, 504 688 cats were insured; this accounted for 1 229 699 cat years at risk (CYAR). Overall DM incidence was 11.6 cases per 10 000 CYAR; 87% were diagnosed as DM, 3% as DM with complication, 4% as DM without complication, and 6% as DM with ketoacidosis. Male cats had twice the DM incidence rate as did females.

In addition to European shorthairs, at-risk breeds included Burmese, Russian blue, Norwegian forest cat, and Abyssinian. When the data were age-standardized, the Devon rex/sphynx breed group was also at increased risk. The age-standardized data identified the Bengal, Birman, Persian, ragdoll, and British shorthair breeds as low-risk.

DM was more common in older cats with a mean age at diagnosis of 10.7 (± 3.1) years. No evidence of increasing DM incidence in cats in Sweden was found during this study period.

The most fascinating findings are the increasing likelihood of diagnosis with age and the duration of claims for 4 or more years. These suggest both a higher peak age of onset and survival beyond typical expectations. The limited number of complicated diabetic cases may reflect a lack of treatment or a low incidence of complicated diabetes because of other factors. Conscientious veterinary care may explain the lack of increased diabetes incidence. Given that this population has some different characteristics than those previously reported for diabetic cats, a more focused prospective study may help elicit differences in husbandry, lifestyle, genetics, and nutrition of Swedish cats that might explain the findings.—Ewan Wolff, DVM