An owner, whose dog was successfully treated for heartworms with melarsomine 2 weeks ago, calls and is quire frustrated at having to keep the dog inside or on leash-only-exercise. "He seems fine and is very energetic. Can he be allowed to run in the fenced-in backyard?" What should you say?
While the dead adult heartworms are breaking down, large chunks of these worms may float down the bloodstream from the heart and lodge in the lungs, where they can cause pulmonary emboli and severe inflammation that can potentially kill the dog. If the dog exercises or gets really excited and the heart beats more rapidly and forcefully, there is a greater chance of a large chunk of worm breaking off and causing this severe reaction. While this is more likely to occur during the first 2 weeks after adulticide therapy, these reactions can occur up to 4 to 6 weeks after adulticide treatment.