Heartworm disease is a preventable but devastating parasite infection in dogs. Understanding prevention and the welfare cost of untreated disease motivates proactive protection.
Untreated heartworm disease causes progressive and serious suffering. As worm burden increases, dogs experience exercise intolerance, coughing, difficulty breathing, and heart failure. The worms physically obstruct blood flow through the heart and lungs. Dogs in advanced heartworm disease may collapse with minimal exertion. Treatment, while effective, requires arsenic-based injections and months of strict cage rest during which the dying worms are reabsorbed - a period with its own welfare challenges. The welfare case for prevention is overwhelming: a $10-$15 monthly preventative tablet eliminates essentially all risk of a disease that causes months to years of progressive suffering and significant welfare harm during treatment.