Heartworm disease is a serious concern in Davidson County, with 1 in 50 dogs testing positive for heartworms. With highly effective parasite preventive products available, however, that high percentage could, and should, be much lower.  Fortunately, our WesVet Animal Hospital team is here to answer any questions you may have about heartworm disease and about how to ensure your pet is protected. 

Question: What causes heartworm disease in pets?

Answer: Heartworms are unlike the majority of “worms” your pet can get, such as roundworms, tapeworms, whipworms, and hookworms. Instead of residing in your pet’s gastrointestinal tract, heartworms set up shop in the blood vessels surrounding the heart and lungs. Immature heartworms, or microfilaria, are transmitted through an infected mosquito’s bite. The microfilaria sneak into your pet’s bloodstream through the bite wound, then spend six months reaching adulthood as they travel to the heart and lungs. Adult heartworms can reach up to a foot in length in dogs, and, as the heartworms grow, they can be fatal to your dog if left untreated.

Q: Can all pets get heartworm disease?

A: Yes. In fact, any mammal, including people, can develop a heartworm infection. However, dogs and wild canines are the preferred host; heartworms typically die off sooner in a less-than-optimal host, such as cats.

Q: What signs will my pet show if they develop heartworm disease?

A: Heartworm disease appears differently in cats than in dogs. In dogs, the most common signs of early-stage infection include:

  • Mild, persistent cough
  • Reluctance to exercise
  • Fatigue after exercise
  • Decreased appetite
  • Weight loss

As the disease progresses, dogs may develop heart failure and ascites, or abdominal fluid buildup. 

Cats experience respiratory effects from heartworm disease, in a condition known as heartworm-associated respiratory disease (HARD). Signs can vary greatly and include:

  • Coughing
  • Asthma-like attacks
  • Vomiting
  • Lack of appetite
  • Weight loss
  • Difficulty walking
  • Fainting
  • Seizures
  • Ascites

Unfortunately, the first sign of the disease in some feline cases is sudden death.

Q: How is my pet checked for heartworm disease?

A: Heartworms reside in your pet’s circulatory system, not their gastrointestinal tract, so checking pets for heartworm disease requires a blood sample, rather than a stool sample. With just a few drops of blood and a few minutes in our hospital, we can determine if your pet has a heartworm infection. Some limitations to the in-house heartworm test exist, however. It only detects adult female heartworms, so immature heartworms and adult males can be present, but cause a false negative test. If necessary, we will send blood to an outside laboratory for more specific testing to confirm a diagnosis.

Q: What happens if my pet develops heartworm disease?

A: Treatment for heartworm disease is difficult for both a pet and their owner. In dogs, an arsenic compound is injected deep into their lumbar muscles to kill the adult heartworms, and most dogs require a series of injections, sometimes spaced a month apart. During that month, and an additional month following the final injection, the dog must be kept under strict exercise restriction. If the dog is too active, they can suffer from potentially fatal side effects caused by the dying worms. 

Unfortunately, no heartworm treatment is available for cats. Supportive care is the only option as the cat’s immune system fights to eradicate the heartworms.

Q: How can I protect my pet from heartworms?

A: Heartworm disease and treatment are incredibly hard on your pet, so protect them with year-round prevention measures. A variety of heartworm preventives are available for cats and dogs, and come in topical, oral, and injectable forms. The key is to ensure your pet receives their dose on time, every time. A single skipped dose in the winter can lead to heartworm disease by summer. 

You can also reduce your pet’s risk for heartworm disease through environmental control. Eliminate standing water sources that are attractive to mosquitoes, such as flower pots, trash cans, and other containers. Check your window screens for rips and tears to ensure mosquitoes can’t sneak in. Stick to dry, sunny areas when walking your dog as most mosquito species prefer moist, shady spots. By taking these steps and keeping your pet on year-round heartworm prevention, your four-legged friend can remain safe from harm.

Ensure your pet is heartworm-negative before stocking up on heartworm prevention medicine. Contact our WesVet Animal Hospital team for an appointment.