Diabetes mellitus in dogs requires lifelong twice-daily insulin injections and dietary management, with well-controlled diabetic dogs achieving good quality of life but poor control causing serious welfare harm.
Canine diabetes creates a welfare management challenge that requires sustained owner commitment over the dog's remaining life. The twice-daily insulin injection schedule demands consistent timing aligned with consistent feeding — disruption to either causes dangerous glucose instability. Dogs that are well-regulated on insulin achieve normal energy levels, appetite, and behaviour, with welfare comparable to non-diabetic dogs. Poorly controlled dogs experience the cumulative welfare harms of chronic hyperglycaemia: persistent excessive thirst and urination, progressive weight loss, and the acute crisis of DKA when glucose control fails entirely. DKA is a medical emergency causing vomiting, lethargy, and collapse — affected dogs are profoundly ill within hours. Cataract development affects the majority of diabetic dogs and causes progressive vision loss over months — the welfare impact varies with how quickly adaptation occurs, but cataract surgery in appropriate candidates restores vision and substantially improves quality of life. Owner education about recognising instability and responding with appropriate urgency prevents most preventable crises.