Diabetes mellitus is a complex metabolic disorder characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. While extensively studied in humans, diabetes mellitus also affects various animal species, including dogs, cats, and rodents, among others. The etiology of this disease involves a combination of genetic predisposition and environmental factors. Certain breeds of dogs and cats exhibits a higher susceptibility to diabetes mellitus, suggesting a genetic component in disease pathogenesis. Clinical manifestations of diabetes mellitus in animals resemble those observed in humans and include polyuria, polydipsia, polyphagia, weight loss, and lethargy. Accurate diagnosis is essential and typically involves a combination of clinical signs, physical examination findings, laboratory tests, and imaging studies. Management of diabetes mellitus in animals aims to achieve glycemic control, prevent complications, and improve quality of life. Close monitoring of blood glucose levels and regular veterinary follow-up are crucial for adjusting treatment regimens and optimizing outcomes.