Dog Heartworm Disease Prevention and Welfare

Heartworm disease is a preventable but serious parasitic infection that causes progressive cardiovascular damage and significant suffering in untreated dogs.

Key Facts

Heartworm is transmitted by mosquitoes and causes worms up to 12 inches long to live in the heart
The disease is endemic across the United States and in many tropical countries
Treatment of established infection is expensive, risky, and requires months of strict rest
Prevention with monthly or annual medications is nearly 100% effective
Dogs with advanced heartworm disease have significant heart and lung damage
Wildlife including coyotes and foxes serve as reservoir hosts making elimination impossible

Welfare Considerations

Dogs with heartworm disease experience progressive cardiovascular compromise as worms proliferate in the heart and pulmonary arteries, causing reduced exercise tolerance, coughing, and eventually heart failure. Treatment involves a series of arsenic-based injections and months of strict exercise restriction to prevent life-threatening complications as dead worms are resorbed. The welfare impact of preventable heartworm infection is severe and prolonged, making consistent prevention the clear choice for dog welfare.

What You Can Do

Administer heartworm prevention on the recommended monthly or annual schedule without gaps
Test dogs annually for heartworm even when on prevention to catch failures early
Consult your vet about the appropriate prevention product for your geographic area
Begin prevention year-round in endemic areas rather than seasonally
Support low-cost heartworm testing and treatment programs in underserved communities