Heartworm disease is an often-discussed, but still misunderstood, condition. This complex mosquito-borne illness can be difficult to explain and understand, but knowing how to protect your furry pal from this threat is a vital part of their health care. Our Mill Creek Animal Hospital team shares 10 essential facts about heartworm disease that every pet owner needs to know, to help keep their pet safe from this mosquito-borne menace.

#1: Any pet can get heartworm disease

Most people think of heartworm disease as canine-only, but this condition can affect all mammals, including cats, ferrets, seals, and people. However, don’t start taking your pet’s heartworm preventive every month—unlike dogs and wild canines, you are not the preferred host. Cats also are not a preferred host, but are much more likely to contract heartworm disease than you, making prevention critical for cats as well as dogs.

#2: Heartworm disease is not only a summertime threat

As the temperature warms up and mosquitoes make their irritating presence known, you may think your pet needs heartworm prevention only at this time of year, but mosquitoes are hardy pests that can emerge from their winter-time lair any time the temperature rises above freezing. And, you’ve likely seen insects in your home in the dead of winter, so you know your indoor pet also isn’t safe. Ideally, heartworm preventives should be administered year-round to ensure your furry pal doesn’t play host to a circulatory system full of parasites. 

#3: Heartworms in your pet can be difficult to detect

The heartworm life cycle is convoluted, and testing requires a unique situation for an accurate diagnosis. Unlike some other worms, you cannot see heartworms in your pet’s stool. Instead, these parasites reside in the blood vessels surrounding the heart and lungs. The larvae travel from the mosquito-bite location and grow and mature, finally reaching adulthood and their final destination after about six months. If your pet is tested for heartworm disease prior to the heartworms reaching adulthood, they’ll receive a false negative result. Additionally, if the heartworm population is all male, the test will also show a false negative, since only adult female heartworms are detected. 

Because a heartworm test is so sensitive, annual testing is necessary to ensure no gaps occurred  in prevention administration, or no immature female heartworms reached adulthood.

#4: Heartworm treatment for your dog can be a long, difficult process

If your dog contracts heartworm disease, treatment can take months. During this time, your dog must be exercise-restricted to ensure the dying parasites have no adverse effects. Treatment involves injecting an arsenic compound deep into the lumbar muscles, which can be extremely painful. Some dogs may need three injections to completely clear the worm burden, but the injections must be spaced apart to minimize complications.

#5: No heartworm treatment is available for cats

While a heartworm treatment exists for dogs, no formula is approved for cats. Instead, treatment focuses on supportive care and managing heartworm-associated signs.

#6: Many heartworm preventives are easy to administer

You may think your cat will have to skip their heartworm preventive because there’s no way they will swallow a pill, but many alternatives are available. Pets can be protected through chewable tablets, topical medications, and injectable heartworm prevention. Ask your Mill Creek veterinarian about the best choice for your pet.

#7: Heartworm prevention protects your pet in a unique way

Unlike flea and tick prevention, which works by repelling or killing these pests, heartworm prevention works retroactively. This means that your pet’s monthly dose kills the immature heartworms before they reach adulthood. For example, if an infected mosquito bites your pet and transmits the heartworm larvae on April 2, the preventive administered on April 1 will not affect those heartworms, but the May 1 preventive will kill them.

#8: Heartworms cannot be directly transmitted from pet to pet

Heartworm disease is not contagious. The heartworm must go through the mosquito to complete its life cycle, so an infected mosquito has to bite your pet for them to contract the disease.

#9: Signs of heartworm disease differ in cats and dogs

Heartworm disease signs in dogs are subtle at first, and gradually progress. Affected dogs may cough, display exercise intolerance, fatigue, and a poor appetite. In severe cases, dogs may develop congestive heart failure, which can create breathing difficulties and a rounded, fluid-filled abdomen.

Cats can display a range of signs that most commonly appear as asthma-like attacks. However, they can also have seizures, difficulty walking, and may suddenly collapse.

#10: Heartworm disease can be fatal if left untreated

Without treatment, heartworms can continue to grow and damage the heart, lungs, and surrounding blood vessels. Late-stage heartworm disease is typically seen with heart failure, which will ultimately prove fatal.

Don’t leave your pet unprotected from the deadly threat of heartworm disease. Schedule an appointment for a heartworm test and physical exam, and then stock up on prevention products. Give your Mill Creek Animal Hospital team a call to schedule an appointment.