April is Heartworm Awareness Month, making it the perfect time to discuss this potentially fatal disease that affects dogs and cats. Despite being entirely preventable, heartworm disease continues to pose a serious risk to pets across the country—including right here in Michigan. At Family Friends Veterinary Hospital, we’re committed to educating pet owners about heartworm prevention, treatment, and the myths that may put pets at risk.
What Is Heartworm Disease?
Heartworm disease is a serious and potentially deadly condition caused by a parasitic worm (Dirofilaria immitis). These worms live in the heart, lungs, and associated blood vessels of infected animals, leading to severe lung disease, heart failure, and organ damage. The disease is transmitted through mosquito bites, making all pets susceptible—even those that spend most of their time indoors.
How Does a Pet Get Heartworms?
Heartworms are spread by mosquitoes that have bitten an infected animal and picked up immature heartworm larvae. When the mosquito bites another animal, it deposits the larvae into their bloodstream. Over the next several months, these larvae grow, mature, and eventually lodge in the heart and lungs, where they cause extensive damage.
This cycle is why year-round prevention is critical—one infected mosquito can pass heartworms to your pet, even in colder months when mosquito activity is lower but not eliminated.
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Signs and Symptoms of Heartworm Disease
Heartworm disease progresses over time, and symptoms may not appear until significant damage has occurred. Here are the signs to watch for:
In Dogs:
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- Persistent cough
- Fatigue after mild activity
- Weight loss and decreased appetite
- Difficulty breathing
- Swollen belly due to fluid buildup in severe cases
In Cats:
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- Coughing or asthma-like symptoms
- Vomiting (often unrelated to eating)
- Weight loss
- Sudden collapse or sudden death in extreme cases
Unlike dogs, cats are not typical hosts for heartworms, so they may only develop a few worms or none at all. However, even a single worm can cause significant respiratory and heart problems in cats.
Diagnosis and Treatment of Heartworm Disease
Diagnosing heartworm disease requires a blood test to detect the presence of heartworm proteins. If a test comes back positive, additional tests such as x-rays or ultrasounds may be needed to determine the severity of the infection.
Treatment for Dogs
Heartworm treatment in dogs is expensive, risky, and requires months of restricted activity. It involves a series of injections to kill the worms, followed by a strict rest period to prevent complications. The treatment process can cost hundreds to thousands of dollars and does not reverse the damage already done to the heart and lungs.
Treatment for Cats
Unfortunately, there is no safe treatment for heartworms in cats. The focus is on managing symptoms and preventing further infections. This is why prevention is absolutely essential for both cats and dogs.
The Best Protection: Year-Round Heartworm Prevention
The good news is that heartworm disease is 100% preventable with monthly preventive medications or an annual injection for dogs. These medications kill heartworm larvae before they have a chance to mature into adult worms.
Prevention options include:
- Monthly chewable tablets or topical treatments (for both dogs and cats)
- An annual injection (for dogs only)
- Combination products that protect against other parasites, such as fleas and intestinal worms
We recommend discussing the best heartworm prevention plan for your pet with our veterinary team at Family Friends Veterinary Hospital. Prevention is far more affordable (and safer) than treatment—especially when considering that heartworm disease can be fatal.
Photo from Pexels
Common Heartworm Myths That Put Pets at Risk
Misinformation about heartworm disease can lead pet owners to make risky decisions. Here are some of the most common myths—and the truth behind them:
Schedule Your Pet’s Heartworm Test and Prevention Today
Heartworm disease is a silent but deadly threat that is far easier to prevent than treat. At Family Friends Veterinary Hospital, we recommend annual heartworm testing and year-round preventive care to keep your pets safe.
If your pet isn’t currently on heartworm prevention or needs a refill, schedule an appointment with us today! Let’s work together to keep your pets happy, healthy, and heartworm-free.
