Heartworm disease is a devastating parasitic infection in dogs that is almost entirely preventable. Understanding the disease and prevention priorities protects dogs from significant suffering.
Heartworm disease exemplifies the welfare principle that prevention is categorically better than treatment. A dog with established heartworm disease faces months of suffering - the worms cause progressive cardiovascular damage, the treatment itself involves painful injections and strict confinement, and complications including pulmonary embolism from dying worms are life-threatening. Dogs undergoing treatment must be strictly confined for weeks to prevent their hearts from failing under exertion. Monthly preventive medication costs pennies per day compared to thousands of dollars for treatment, yet millions of dogs remain unprotected due to owner unawareness or cost concerns. Ensuring access to affordable prevention is one of the most impactful companion animal welfare interventions available.