Diabetes mellitus in dogs — caused by insulin deficiency or resistance — requires daily insulin injections and careful dietary management, and significantly impairs quality of life if poorly controlled, but allows good welfare outcomes with dedicated owner care.
Uncontrolled diabetes causes chronic suffering through osmotic diuresis, muscle wasting, and ketoacidosis. Dogs that are well-regulated — with stable blood glucose, good body condition, and normal energy — can enjoy excellent quality of life despite requiring daily insulin. The welfare burden falls significantly on owners, who must commit to twice-daily injections, consistent feeding schedules, and regular veterinary glucose monitoring. Cataract development and subsequent blindness is a common and significant welfare complication: cataract surgery can restore vision, but is not accessible to all owners. The key welfare message is that diabetes is manageable, and dogs should not be euthanised at diagnosis — with appropriate owner education and commitment, a good life is achievable.