Canine heartworm disease, caused by Dirofilaria immitis, is a serious parasitic infection transmitted by mosquitoes, causing progressive cardiopulmonary disease that is entirely preventable with monthly medication.
Heartworm disease causes progressive cardiopulmonary impairment that limits exercise, causes chronic coughing, and eventually leads to heart failure. The treatment of established disease involves months of restricted activity and the risk of pulmonary thromboembolism as adult worms die. The treatment itself, while necessary, causes temporary welfare compromise. Prevention with monthly macrolide antiparasitic medication is cheap, safe, and completely effective, making established heartworm disease in dogs with appropriate access to veterinary care an entirely preventable welfare burden.