Feline heartworm disease is less common than in dogs but causes more severe individual welfare impacts, making prevention critically important in endemic regions.
Feline heartworm disease causes acute and often fatal respiratory crises with minimal warning. Cats that develop heartworm-associated respiratory disease experience sudden severe breathing difficulty as the immune response to dying worms triggers catastrophic pulmonary inflammation. Unlike dogs, there is no treatment that safely clears adult worms - affected cats either manage the inflammation and survive or die during a crisis episode. The welfare implications are severe: preventable acute suffering and sudden death in cats that were apparently healthy. Monthly prevention is inexpensive and completely effective at preventing disease, making every case of feline heartworm disease a preventable welfare failure.