Heartworm disease causes serious suffering and preventable death. Year-round prevention is among the most impactful preventive welfare interventions available to dog owners.
Heartworm prevention exemplifies the principle that preventive medicine is the most welfare-positive intervention: a simple monthly medication prevents disease causing severe suffering and difficult, expensive treatment. Heartworm-infected dogs experience progressive cardiopulmonary damage, exercise intolerance, coughing, and heart failure — a prolonged suffering course that prevention eliminates entirely. Treatment involves months of restricted activity, multiple injections, and significant welfare cost from the dying worms causing inflammatory lung disease. The cost comparison is stark: prevention costs dollars monthly; treatment costs hundreds to thousands of dollars and causes significant animal suffering. Making heartworm prevention a standard of care for dogs in endemic areas is one of the highest-ROI welfare interventions available — cheap, safe, and highly effective at preventing serious disease.