What are some measures to prevent heartworms?

consult an animal doctor and take the medicine they give you.
There are a number of preventative medications on the market. After a simple test, your veterinarian will prescribe them to you. The test must be preformed to make sure your pet has not already become infected. Treating an animal that is already infected could cause complications. The most common medications are in tablet or pill form and given orally once a month during 'mosquito season'. There are also topical treatments for dogs such as Advantix that will help keep mosquitoes away from your pet. However, this is not actually marketed as a preventative for heart worms. It is just an extra step. It also helps not let stagnant water accumulate in your yard where your pet may drink it. This is where mosquito larvae will be.