Unfortunately, many myths and misconceptions about heartworm disease continually swirl around, which can lead to deadly consequences for your pet. Our Fairfax Veterinary Clinic team sets the story straight about this parasitic disease, so you can better protect your four-legged friend.

Myth: Only pets who live outdoors get heartworm disease.

Fact: While pets who live outdoors are certainly at much higher risk, indoor-only pets can also contract heartworm disease. Mosquitoes can dart in through open doors, or slip through tiny tears in window screens, searching for their next meal. So, your dog who heads outside to use the bathroom is not the only one at risk for heartworm disease—so is your cat who never ventures a whisker outdoors. 

Myth: Heartworm disease is only a concern during summer months.

Fact: Fairfax, California, is not known for frigid winter months, so we experience pesky parasites all year long and pets can get heartworm disease at any time. And, places whose winter temperatures are below freezing most of the time are not much safer, because mosquitoes can become active on one mild day above 35 degrees. Plus, mosquitoes can overwinter in your garage, sneak into your home, and infect your pet, so no place is truly safe from heartworm disease in winter.

Myth: My pet can get heartworm disease from other pets.

Fact: Unlike other parasitic infections (e.g., roundworms, whipworms), your pet cannot get heartworms directly from another pet. Pets are infected by mosquitoes who have bitten another infected pet and ingested larvae, which begin maturing in the mosquito. When the mosquito bites your pet, they inject the larvae, which mature inside your pet over several months, eventually growing up to a foot in length and traveling through their bloodstream to their lung vessels and their heart. So, while the heartworm-infected pet down the road is cause for concern, they cannot infect your pet.

Myth: I would know if my pet had heartworm disease.

Fact: Heartworm disease can be difficult to detect in pets, particularly dogs with early stage disease, because signs can take months to become obvious. You may not realize your pet has heartworm disease until their condition has advanced to a more serious stage that is extremely difficult to treat.

A dog with heartworm disease will first exhibit a mild, persistent cough that worsens over time, followed by exercise intolerance, lethargy, and inappetence. As the disease progresses, your dog’s abdomen will become bloated from fluid accumulation and congestive heart fluid will be the end result.

Cats with heartworm disease can show a range of vague signs that may mimic asthma. Signs can include:

  • Wheezing
  • Coughing
  • Vomiting
  • Difficulty walking
  • Appetite and weight loss
  • Fainting episodes
  • Seizures

In some cases, the first—and only—heartworm disease sign in cats is sudden collapse or death.

Myth: My pet doesn’t need an annual heartworm test because they’ve been on a prevention plan.

Fact: You may give your pet their heartworm preventive on time, every time, but accidents do happen. Your pet may have vomited up their oral tablet, or rubbed off their topical product, so their preventive was ineffective. Detecting and treating heartworm disease early means your pet suffers less permanent damage. Plus, should your pet develop heartworm disease despite prevention, the manufacturer may have to cover your pet’s treatment costs if you have proof they were tested annually for heartworm, and received preventives the entire year.

Myth: Heartworm disease treatment is as easy as prevention.

Fact: Unfortunately, heartworm disease treatment is much more difficult and costly than prevention. Infected dogs have to undergo a series of intramuscular injections deep in their lumbar muscles, which can cause severe pain and nausea. During treatment, the dog must remain calm and quiet and cannot exercise. Treatment typically takes a month, followed by a six-to-eight-week recovery period. A dog who is too active is at risk of potentially fatal side effects from blockages of dying worms.

For cats, no approved heartworm disease treatment is available. All you can provide is supportive care for any signs such as pain while you wait for the cat to—hopefully—outlive the heartworms.

You can see that heartworm disease prevention is much simpler, for you and your pet. Heartworm preventives are available in oral, topical, or injectable forms, and some also treat intestinal parasite infections and provide flea and tick prevention, protecting your pet from a multitude of parasites.We know heartworm disease, prevention, and treatment can be confusing for pet owners, especially given all the misinformation available. But, knowing the truth about heartworm disease is incredibly important for keeping your four-legged friend safe. Give our Fairfax Veterinary Clinic team a call to determine the best heartworm prevention plan for you and your pet.