How does a dog or cat get heartworm?
Dogs and cats get heartworms when they are bitten by a mosquito that is carrying the larvae. If the dog or cat is not taking a heartworm preventive, the larvae that are injected into the bloodstream will circulate and grow and develop into mature heartworms. This takes about 6 months. If the dog or cat is taking a preventive medication, the larvae will not be able to develop into adults and the pet will not become infected. Adult heartworms live in the blood vessels of the lungs and also in the heart if the numbers are very high. This can lead to congestive heart failure. Dogs may have infections with hundreds of worms, while cats may only have a few worms. Often the first symptom of a heartworm infection is weight loss, especially in dogs. Once there are symptoms of heart failure, such as exercise intolerance or coughing, the infection is advanced. There is no treatment for heartworm infection in cats. Dogs can be treated with a poison that will kill the worms. The treatment is expens
