Heartworm disease is a preventable but potentially fatal condition in dogs caused by parasitic worms in the heart and lungs. Understanding prevention and early treatment protects dogs from severe suffering.
Heartworm disease causes prolonged, progressive suffering that is entirely preventable with inexpensive monthly medication. Adult worms cause physical obstruction of the heart and major blood vessels, leading to heart failure, exercise intolerance, and respiratory distress that worsens over months to years. Dogs with advanced disease experience chronic exhaustion and respiratory distress as a baseline state of existence. The treatment protocol, while necessary, is itself physically demanding and requires weeks of strict rest. The welfare case for prevention is overwhelming: monthly preventives cost a fraction of treatment, cause no discomfort, and spare dogs from months or years of progressive suffering. Veterinary outreach and low-cost prevention programs that ensure access to preventives in high-risk regions are high-impact welfare interventions.