Insulin and Glucagon Dynamics in Naturally Occurring Feline Diabetes Mellitus in Port Harcourt, Rivers State

Diabetes mellitus is an increasingly recognised metabolic endocrinopathy in cats, particularly in ageing, neutered, or obese individuals. In Port Harcourt, Rivers State, South South Nigeria, the companion animal veterinary sector has seen a rising incidence of feline diabetes cases, but pancreatic hormone dynamics in affected animals have not been described in the regional literature. This study characterised plasma insulin and glucagon concentrations in cats with naturally occurring diabetes mellitus compared with healthy control cats presented at small animal clinics in Port Harcourt. Twenty diabetic and 20 healthy age-matched cats were enrolled. Diabetes was confirmed based on persistent hyperglycaemia above 14 mmol/L, glucosuria, and compatible clinical signs. Blood samples were collected after a four-hour fast for measurement of fasting plasma insulin, glucagon, glucose, fructosamine, and cholesterol. Insulin concentrations were significantly lower in diabetic cats, with 14 of 20 having undetectable insulin by ELISA, consistent with absolute insulin deficiency. Six diabetic cats had low but detectable insulin, suggesting relative deficiency. Glucagon concentrations were significantly elevated in diabetic cats compared with controls, indicating glucagon excess contributing to hyperglycaemia. Fructosamine was elevated in all diabetic cats, confirming chronic hyperglycaemia. Cholesterol was significantly higher in diabetic animals. These results characterise the endocrine pancreatic profile of feline diabetes in the Port Harcourt context and support a predominantly type 1-like pathology, informing insulin replacement as the primary therapeutic approach in Nigerian companion cat diabetic management. Keywords: feline diabetes, insulin, glucagon, Port Harcourt, endocrinopathy.