Heartworm disease causes severe, progressive cardiac and pulmonary damage in dogs. Prevention is simple, inexpensive, and highly effective — making it a fundamental welfare responsibility for dog owners.
Heartworm disease causes progressive suffering over months to years as worms damage the pulmonary vasculature and heart. Affected dogs experience exercise intolerance, coughing, and eventually signs of right-sided heart failure including fluid accumulation and respiratory distress. The suffering involved in advanced heartworm disease is significant and prolonged. The welfare tragedy is that this entirely preventable condition affects hundreds of thousands of dogs annually because of barriers to access — cost, lack of veterinary relationship, or owner knowledge gaps. Heartworm prevention is one of the clearest welfare responsibilities of dog ownership in endemic areas, with low cost and virtually no side effects making failure to prevent difficult to justify on resource grounds for most owners.