Dog Heartworm Prevention in Endemic Regions

Heartworm disease causes serious cardiopulmonary damage in dogs in endemic regions. Preventive medication is simple, safe and highly effective, making prevention the primary welfare strategy.

Key Facts

Heartworm (Dirofilaria immitis) is transmitted by mosquitoes and endemic across much of the Americas, southern Europe and parts of Asia
Adult worms live in the heart and pulmonary vessels causing progressive damage over years
Clinical signs including coughing, exercise intolerance and eventually heart failure develop gradually
Monthly preventive medication (milbemycin, ivermectin) or annual injections prevent establishment of larvae
Treatment of established infection is complex, expensive and carries significant risks compared to prevention

Welfare Considerations

Heartworm disease causes progressive cardiopulmonary suffering over years as worm burden accumulates. Affected dogs gradually lose exercise capacity and develop respiratory distress before heart failure. Treatment causes additional welfare costs from the necessary exercise restriction during larval die-off. Prevention is overwhelmingly preferable from both a welfare and practical perspective and is highly reliable when administered consistently.

What You Can Do

Administer monthly heartworm prevention year-round for dogs in endemic regions
Test dogs annually for existing heartworm infection before starting prevention
Consult a vet about appropriate preventive products for your region and dog size
Maintain preventive treatment throughout life not just during apparent mosquito seasons
Test dogs returning from endemic regions and implement prevention if not previously given