Heartworm disease, caused by Dirofilaria immitis transmitted by mosquitoes, causes severe cardiopulmonary welfare impairment in infected dogs with a demanding and painful treatment protocol - making prevention paramount.
Heartworm disease causes welfare harm across two distinct phases: the chronic progressive cardiopulmonary disease of infection, and the demanding treatment protocol required for cure. Infected dogs experience exercise intolerance, coughing, and respiratory distress that worsens progressively over years as worm burden increases. Treatment, while curative, involves multiple intramuscular injections of an arsenic-based compound that causes local pain, combined with weeks of strict cage rest to prevent fatal pulmonary embolism as worms die. The entire disease trajectory - infection, progression, and treatment - represents a welfare burden that is entirely preventable through consistent monthly preventive administration. Prevention cost is a fraction of treatment cost.