Heartworm Prevention Is Cheaper Than Treatment

The Math Is Simple — Prevention Wins

Here’s a number that gets every pet owner’s attention: treating heartworm disease in a dog costs between $1,000 and $5,000, depending on severity. Monthly heartworm prevention costs under $15 (depending on the prevention and the size of your pet). That’s less than a dollar a day to protect your pet from one of the most dangerous parasites in Florida.

At Community Animal Hospitals in St. Petersburg, our veterinarians Dr. Leslie Block and Dr. Mark Williamson treat heartworm-positive dogs every month — and many of those cases were entirely preventable. Here’s what every pet owner in South Pinellas County needs to know.

How Heartworm Disease Works

Heartworms are transmitted through mosquito bites. When an infected mosquito bites your dog, it deposits microscopic heartworm larvae into the skin. Over the next six months, those larvae migrate through your dog’s body and mature into adult worms that live in the heart and pulmonary arteries. Adult heartworms can reach 12 inches long, and a single dog can harbor dozens of them.

The damage is devastating. Heartworms cause inflammation in the blood vessels, restrict blood flow, and force the heart to work harder. Left untreated, heartworm disease leads to heart failure, lung disease, organ damage, and death.

Why Florida Is Ground Zero

Florida consistently ranks among the top states for heartworm infections, and the Tampa Bay area is a hot spot. Our warm, humid climate supports mosquito populations year-round. There is no “mosquito season” in St. Petersburg — mosquitoes are active every single month. This means your pet faces constant heartworm exposure, which is why year-round prevention is non-negotiable here.

Even indoor cats are at risk. Mosquitoes easily get inside homes, and it only takes one bite. While heartworm in cats is less common, it’s more dangerous — there is no approved treatment for heartworm disease in cats, making prevention the only option.

What Treatment Actually Involves

If your dog tests positive for heartworms, treatment is a months-long process that’s hard on your pet and your wallet:

• Diagnostic workup — bloodwork, X-rays, and sometimes echocardiography to assess damage
• Stabilization — dogs with advanced disease may need treatment for heart failure before addressing the worms
• Melarsomine injections — the drug that kills adult heartworms is given as a series of deep intramuscular injections over several months
• Strict exercise restriction — for months during and after treatment, your dog must be kept calm and quiet because dying worms can cause dangerous blood clots
• Follow-up testing — multiple heartworm tests over the following year to confirm the infection is cleared

The total cost typically runs $1,500 to $3,000 for moderate cases, and severe cases requiring hospitalization can exceed $5,000. Compare that to roughly $100-$180 per year for monthly prevention.

Prevention Options That Work

Modern heartworm preventives are safe, effective, and convenient. Options include:

• Monthly chewables — flavored tablets most dogs take like treats (Heartgard, Simparica Trio, Interceptor)
• Monthly topicals — applied to the skin (Revolution, Advantage Multi)
• Injectable — ProHeart 6 or ProHeart 12 provides 6 or 12 months of protection with a single injection at the vet’s office

Many of these products also protect against intestinal parasites like roundworms and hookworms, giving you even more value for your investment.

Don’t Let a Missed Dose Become a Crisis

If you’ve missed a month or two of prevention, don’t panic — but don’t wait either. Give the next dose immediately and call us to schedule a heartworm test. It takes six months for an infection to become detectable, so your vet may recommend retesting in six months to be sure.

The bottom line: heartworm prevention is one of the best investments you can make in your pet’s health. Call Community Animal Hospitals at (727) 592-1816 to get your pet started or refill their prescription today.