Diabetes mellitus in dogs and cats

Diabetes mellitus (DM) is a common endocrine disease in dogs and cats, and whose incidence is increasing. The classification of DM in these species is oriented towards the human diabetes classification. In dogs, a type 1 DM is found, resulting from an autoimmune-mediated destruction of the beta cells of the pancreas. Feline DM is most commonly type 2, which is caused by insulin resistance, obesity and amyloid disposition in the pancreas. Another specific type of DM (type 3), caused by other diseases or the use of drugs, is possible in both species. Regardless of the underlying aetiology, the hyperglycaemia is treated with exogenous insulin. Currently, porcine insulin and human recombinant insulin are used in veterinary medicine. Besides insulin, dietary management and good monitoring are necessary for successful treatment. Cats can go into remission. Insulin resistance can occur during the course of disease. Complications leading to insulin resistance can be technical problems, other underlying diseases (e. g. secondary endocrine disease, bacterial infection, pancreatitis, neoplasia) and diabetogenic drugs. In such cases, a comprehensive re-evaluation of the patient is needed, which can be challenging for the veterinarian.