Heartworms

What You Need to Know

Heartworms live in the heart, lungs, and arteries of their host and can be very serious and sometimes even fatal. These roundworms can affect many mammals, including cats, dogs, foxes, and humans. The disease is spread by mosquitoes, which bite their victims and deposit heartworm larvae under the skin. They eventually reach the bloodstream by eating through the skin and connective tissue. From there they are transported through the blood to the lungs and arteries where they will grow into adults. Heartworms can live for up to seven years and can produce offspring after six months. Believe it or not, males can grow up to eight inches long, while females can reach 12 inches.

Short hair dogs are more prone to heartworms simply because it's easier for mosquitoes to bite them. Infection rates are highest along the Gulf and Atlantic coasts, though heartworms can be found throughout the United States. Like many other dangerous diseases, heartworms can also spread from dog to dog through feces. The parasite can cause permanent damage to those infected, which makes it crucial to treat your pet as soon as possible. The most effective way to avoid heartworms is with preventative medication.

Diagnosing Heartworms

• Blood Tests – There are two tests, microfilaria and heartworm antigen tests, that are frequently used to diagnose heartworms.
• Physical Tests – A physical examination by itself can be difficult to accurately perform, as mild infections often don’t show any signs. For that reason, a blood test is often used to accompany a physical test. If a dog is severely infected, he or she may show signs of fatigue, heart failure, rapid heartbeat, coughing, loss of appetite, enlarged liver, or jaundice. Physical tests also include x-rays and ultrasounds on the heart and lungs.

Treatments for Heartworms

Heartworm is often successfully treated in dogs. Treatments include adulticide injections, which are the only FDA-approved drug for heartworms. There are some risks associated with this treatment, including blood vessels becoming filled with dead worms, which can cause death as a result of blocked blood flow.

If a dog has a severe case of heartworms, it can be difficult to treat, as one dose of adulticide is often insufficient. Your dog will require an antigen test six months after the first dose to determine if another treatment is necessary. During treatment, it is crucial that your dog does not exercise, as their pulmonary system will be under strain.

Contact Your Vet with Questions

DoodyCalls is by no means an expert on heartworms. We simply want to provide our clients with information to educate them on some of the situations they may face as a pet owner. If you suspect your dog has heartworms or simply have questions, reach out to your veterinarian for assistance.

The American Heartworm Society has an extensive Web site that contains everything you ever wanted to know about heartworms – and more.

The online encyclopedia Wikipedia also has an extensive entry about canine heartworms.