Dermatologic disorders in dogs with diabetes mellitus: 45 cases (1986-2000)

Objective-To characterize skin lesions and causative infections in diabetic dogs and evaluate other potential causes of dermatologic disorders, includ ing concurrent endocrinopathies, allergic skin disease, and long-term corti costeroid administration. Design-Retrospective study. Animals-45 dogs with diabetes mellitus (DM) that were examined by dermatolo gists. Procedure-Medical records were reviewed for signalment; allergic conditions prior to development of DM; prior corticosteroid administration; and resul ts of dermatologic examinations, ear and skin cytologic examinations, skin scrapings for parasites, bacteriologic and fungal culturing of ear and skin specimens, histologic examinations, and endocrine testing. Results-Bacterial skin infection was the most common dermatologic disorder (n = 38 [84%]), followed by otitis (26 [58%]) and Malassezia-induced dermat itis (19 [42%]). Twenty-two (49%) dogs had pruritic skin disease consistent with allergic dermatitis, which pre ceded diagnosis of DM. Prior corticost eroid administration was reported in 21 (47%) dogs. Concurrent hyperadrenoc orticism was diagnosed in 13 (29%) dogs, and concurrent hypothyroidism was diagnosed in 5 (11%)dogs. latrogenic hyperadrenocorticism was diagnosed in 1 additional dog. Only 10(22%) dogs did not have a documented concurrent en docrinopathy or allergic disease that could have caused the dermatitis. Conclusions and Clinical Relevance-Bacterial and yeast-induced dermatitis a nd otitis develop in dogs with DM. Many diabetic dogs with dermatologic pro blems have a preexisting allergic condition, history of prior corticosteroi d administration, or concurrent endocrinopathy that may be a more likely ca use of dermatologic problems than DM alone.