Heartworms 101

Canine Heartworm Disease
Heartworm infections occur all over the United States but are most prevalent in the South, especially the Gulf Coast states. Heartworms are transmitted by mosquitoes. They carry the heartworm larvae and inject them into the dog’s bloodstream when they take a blood meal from the dog. The larvae then grow over the next 6 months and migrate to the pulmonary arteries within the lungs. When heartworm infections go undetected, they lead to heartworm disease and can cause coughing, respiratory difficulty, lethargy, and eventually heart failure leading to death.

Heartworm infection can be detected through a blood test. The test looks for antigens, which are only produced by adult heartworms. Because heartworm disease is so serious, it’s recommended to test annually at your yearly checkup. Heartworm disease is easily preventable with a monthly medication. There are different types of preventatives, so speak to your veterinarian about which one is best for your pet. Some of these even include medications to prevent intestinal worms and fleas.

The treatment for heartworm disease is a series of injections to kill the adult heartworms and treatments to kill the babies. This treatment can take 2-3 months, depending on the severity of the disease. Treatment is very hard on your pet’s body and they will need to be cage-rested and kept extremely calm during this time. During treatment, there is a rapid kill of all adult heartworms and pets are at a high risk of suffering a pulmonary emboli. This can all be avoided if you use monthly preventative!

It is extremely important to remember that it takes just one mosquito bite to infect your pet with heartworms. Even if your pets stay inside, they are still at risk. Strict monthly prevention is the best way to avoid any future problems with heartworms.

Feline Heartworm Disease
Cats are also susceptible to heartworm infection; however, there is a much lower prevalence than in dogs. Whereas dogs have multiple worms with an infection, cats may only have one. The life cycle is similar in cats and dog. However, infection may spontaneously clear in cats. This is not the case for dogs.

Clinical signs are typically the same. Cats may be lethargic, cough, collapse, and even have sudden death. Sometimes, heartworm disease can even appear as feline asthma.

Testing for heartworms in cats is difficult because of such a low worm burden. A negative antigen test does not necessarily mean that there are no heartworms; however, a positive test indicates infection.

Only cats that test positive and have appropriate clinical signs are treated for heartworm disease. Treatment is much less invasive than in dogs. However, treatment is usually not necessary as most cats may spontaneously recover.

Heartworm disease is also easily preventable in cats with a monthly prevention. As with dogs, some of these preventions also prevent fleas and a multitude of other things. Talk to your veterinarian about which is best for your cat.