Heartworm disease causes severe, progressive suffering in dogs and is entirely preventable through safe, widely available monthly treatments that represent one of the highest-value welfare interventions for companion dogs.
Heartworm represents a preventable welfare crisis in regions where it is endemic. Dogs with established heartworm infection suffer a gradual, progressive deterioration of cardiopulmonary function over months to years before diagnosis. The disease is often subclinical early, meaning dogs may be experiencing significant physiological compromise before owners observe changes. Treatment is stressful, expensive, and requires prolonged strict exercise restriction that is itself a welfare challenge for active dogs. Monthly prevention using flavoured chewable tablets is safe, highly effective, and inexpensive relative to treatment costs. The welfare case for heartworm prevention is overwhelming: the risk of prevention is negligible, the benefit is complete avoidance of a serious chronic disease. Geographic risk is expanding with climate change, making prevention relevant in increasingly wide areas.