Did you know that a single mosquito bite can have serious—sometimes life-threatening—implications for pets? Heartworm disease is a potentially fatal condition that can affect dogs, cats, and other mammals. Understanding the disease and the importance of its prevention can help keep your pet safe and healthy. Our team at Animal Medical Center of Marquette shares essential do’s and don’ts for heartworm prevention.

DO research heartworm disease in pets

Knowledge is power when it comes to protecting your pet from heartworm disease, so educate yourself about the condition, including transmission, signs, treatment, and prevention. Understanding the risks associated with heartworm infection will empower you to make informed decisions about your pet’s health.

In your research on heartworm disease, you will learn the following important information:

  • Heartworms are transmitted by mosquitoes — Heartworms are transmitted through an infected mosquito’s bite. Dogs and wild canids, such as wolves, coyotes, foxes, and raccoons, are natural hosts for heartworms. When a mosquito takes a blood meal from an infected natural host, the parasite matures inside the mosquito and can be transmitted when the mosquito bites another pet. 
  • Heartworms mature and migrate to the heart —When the mosquito bites, immature heartworms (i.e., microfilariae) enter your pet’s bloodstream and migrate to the lung vessels, where they mature over the next six months. The adult heartworms reside in the heart, large pulmonary vessels, and arteries, and cause inflammation of vessels and tissue. They grow up to 12 inches long and reproduce in the hundreds, impairing vital circulation and forming blockages that can cause sudden death in dogs.
  • Heartworm disease looks different in cats and dogs — Heartworm disease in cats differs from dogs. Affected cats usually harbor only one or two adult worms, and circulating microfilariae are rare. Heartworm disease is often undiagnosed in cats because they seldom show signs and get tested. 

DON’T assume your pet is not at risk

Many pet owners mistakenly believe their pet is not at risk of a heartworm infection. While certain geographic areas carry a higher risk, heartworms can infect pets anywhere. Risk factors include:

  • Climate (i.e., temperature and humidity)—A warm, humid climate is highly desirable for mosquitoes
  • The mosquito species in the area
  • Presence of mosquito breeding areas

DO know heartworm disease signs in pets

Because heartworm disease progresses slowly, dogs do not show visible signs until they are severely affected, which can be six or more months after infection. Worse, cats—who are not considered natural hosts for the disease—may show no signs at all. Clinical signs may include:

  • Dogs:
    • Persistent cough
    • Exercise intolerance
    • Fatigue
    • Weight loss
    • Distended abdomen
  • Cats:
    • Coughing or wheezing
    • Asthma attack-like respiratory distress
    • Intermittent vomiting
    • Loss of coordination
    • Seizures
    • Sudden death

DON’T wait to seek medical care if you suspect your pet has heartworms

If you suspect that your pet has heartworm disease, don’t delay seeking medical attention. Early diagnosis and treatment can significantly improve your pet’s prognosis and quality of life. Ignoring possible symptoms or delaying veterinary care can lead to further complications and death in severe cases. A pet can be tested for heartworm infection, with follow-up tests required to determine disease severity.

Heartworm treatment includes medication to kill larvae, antibiotics to eliminate heartworm-associated bacteria, and anti-inflammatory medications. Dogs can be treated with a series of costly, painful arsenic-based injections to kill adult worms and must be exercise-restricted for the treatment duration, to prevent the dying heartworms from causing deadly blood flow obstructions. No treatment is available for cats.

DO have your pet heartworm tested annually

Annual heartworm testing is a critical component of preventive care for pets. Your pet may already be on a heartworm preventive regimen, but routine testing is still necessary to ensure that the medication is effective and your pet remains infection-free. Your veterinarian can perform a simple blood test to detect the presence of heartworm larvae.

DON’T skip a dose of your pet’s heartworm preventives

Consistency is key when it comes to protecting your pet from heartworm disease. Skipping only one dose of prescribed heartworm preventive medication can leave your pet vulnerable to infection. Heartworm prevention must be used year-round, because mosquitoes can emerge at any time.

DO take precautions to reduce your pet’s exposure risk

While heartworm preventives are essential, you can take additional precautions to reduce your pet’s exposure to mosquitoes, including:

  • Limiting outdoor activities during peak mosquito hours, which are typically dawn and dusk
  • Using pet-safe mosquito repellents
  • Creating barriers with mosquito netting placed around outdoor enclosures 

Heartworm disease is serious and potentially life-threatening. However, by taking proactive measures and following these prevention do’s and don’ts, you can significantly reduce the risk of your pet contracting this harmful disease. Contact Animal Medical Center of Marquette to schedule an appointment for a wellness visit, heartworm test, or parasite control consultation.