Heartworm disease causes serious suffering and is entirely preventable. Understanding transmission, prevention, and the welfare impact of established infection highlights why prevention is essential.
Heartworm disease causes prolonged suffering through progressive heart and lung damage, exercise intolerance that restricts quality of life, and the intensive treatment process that itself causes welfare harm. Prevention is both the welfare and economic priority - monthly preventive medication costs a fraction of treatment and causes none of the suffering of established disease. Dogs that develop heartworm disease often go undetected until significant damage has occurred because early disease is subclinical. The welfare case for universal, consistent prevention is overwhelming. Failure to prevent heartworm is a welfare failure that causes completely avoidable suffering.