Heartworm disease causes severe welfare harm in untreated dogs, yet prevention is simple, inexpensive, and highly effective.
Heartworm disease represents a welfare failure of prevention rather than treatment. The disease itself causes significant suffering — progressive respiratory distress, exercise intolerance, and eventual cardiac failure — but is nearly completely preventable with monthly medication. Many dogs develop heartworm because owners are unaware of the risk, cannot afford prevention, or forget consistent administration. Community programs that provide free or subsidized heartworm prevention in high-prevalence areas and widespread education about the importance of year-round prevention would eliminate a large fraction of this preventable welfare burden.