Heartworm disease is a serious, preventable parasitic infection that causes severe cardiopulmonary welfare harm in dogs, with treatment that is itself physically demanding — making prevention the overwhelmingly preferable welfare strategy.
Heartworm disease causes progressive, debilitating cardiopulmonary welfare harm. Dogs with high worm burdens develop exercise intolerance, cough, breathlessness, and ultimately right heart failure — a trajectory of suffering that worsens over months to years without treatment. The treatment itself imposes a welfare burden: 6-8 months of strict cage rest is distressing for active dogs and demanding for owners. From a welfare standpoint, monthly prevention is unambiguously superior: it is safe, inexpensive relative to treatment, and prevents the entire disease trajectory. The expansion of heartworm into previously non-endemic regions due to climate change means that prevention is increasingly relevant for dogs in temperate climates. Owner awareness of geographic risk and the simplicity of prevention is the most important welfare intervention for this condition.