top menu

Heartworms – Signs and Treatment, by Dr. Maria Badamo

Heartworms

Dr. Maria Badamo

 

What are heartworms?

Heartworms are exactly what the name implies, parasitic worms that live in the dogs heart. They are fairly large worms that can grow up to 14 inches long and can live there for up to 5-7 years. While living in the heart they can cause a tremendous amount of damage, not only to the heart, but also to the lungs, and the kidneys. In addition to organ damage, patients with Heartworms are also at high risk for clots (from the body parts of the worm) to the lungs and the brain.

 

So how do dogs get heartworm disease?

They get them from mosquito bites. All dogs big/small, young/old, long haired or short can be at risk if they are not on year round heartworm prevention.  If a dog is bitten by a mosquito that is carrying the larval form of the heartworm (which is microscopically small) the dog is then injected with baby heartworms. Those worms then migrate through the dog’s body to reach and infect the heart. It takes the baby worms (also called stage 3 larva) 6 months to reach the dogs heart and grow into adult heartworms. As they migrate they continue to grow and mature from Stage 3 larva into stage 4 larva then stage 5 larva (also known as young adult or juvenile stage). When the worms reach the heart they are now the adult worm stage. The adult worms can be males or female worms. Once in the heart the adult female worms can start producing what are called microfilaria (also known as stage 1 larva), which then circulates through the infected dogs blood stream. If a dog that is carrying the microfilaria is bitten by a mosquito that worm is then transmitted to the mosquito completing the life cycle to then be capable of infecting another dog.

 

How do you know if your dog has heartworms?

The American Heartworm Society recommends testing your dog every year for heartworm disease. The test is a blood test that can only detect the antigen from the adult female worm’s body. This is why your pet can have heartworms (young, juvenile worms, or male worms) and still test negative. It takes 6 months after the initial bite and at least one of the worms to be female for the dog to test positive on the heartworm screening test. If your dog has been off prevention for over 2 months, it is recommended to test immediately and then repeat the test in 6 months to make sure that the dog is truly negative for and not carrying heartworm disease.

 

How do we prevent this from happening to your dog?

Year-round Heartworm prevention! Heartworm prevention is aimed at killing the larval 3 and 4 stages of heartworm disease therefore stopping the life cycle and preventing them from infecting your dog’s heart. There are multiple choices for heartworm prevention available. Monthly topicals, monthly oral treats or an injection, called Pro-heart, that will last 6 months. It is strongly recommended that you speak with your dog’s veterinarian to find the best. Heartworm prevention needed for your pet if he or she is not currently protected against heartworm disease.

 

What happens if my dog gets Heartworm disease?

When a dog tests positive for heartworms, retesting to confirm a true positive result is strongly recommended. If the second test is positive, an appointment for consultation with a veterinarian is recommended to discuss a treatment plan for your dog’s heartworm disease. If your dog is positive for heartworms this means that adult heartworms are currently alive in your dog’s heart. The worms can cause side effects in the dog’s heart and lungs, that can include ongoing heart damage, heart failure, coughing, coughing blood, pulmonary thromboembolism (blood clot in the lungs), Stroke (blood clots in the brains), collapse, and sudden death. An ideal treatment plan consists of a multiple step process, and is devised to kill each life stage at different treatment stages, and to minimize the potential side effects from the Heartworms and the treatment.

 

For more information about heartworm disease please visit the American Heartworm Society website – https://www.heartwormsociety.org

Maria Badamo, DVM