Heartworm in Dogs: A Friendly Guide for Peoria, Dunlap, and Kickapoo Dog Families

Whether your dog’s favorite spot is a trail walk along the Rock Island Greenway, a backyard in Dunlap, or a muddy creek bank out in Kickapoo, one tiny thing can follow them everywhere: the mosquito. And around here, mosquitoes can bring heartworm along for the ride.

If you just got the call that your dog tested positive, first, take a deep breath. Heartworm is serious, and it is also very treatable. Most dogs who finish treatment go right back to stealing socks and hogging the couch. This guide walks you through what heartworm is, what happens after a positive test, how treatment works, and how to keep your pup protected from here on out.

What Is Heartworm, Anyway?

Heartworm is a parasite that lives in a dog’s heart and in the big blood vessels of the lungs. Adult worms can grow up to a foot long, and a dog can carry dozens of them. Over time they damage the heart, the lungs, and the blood vessels in between.

Dogs get heartworm from exactly one thing: a mosquito bite. A mosquito bites an infected animal, picks up baby heartworms, and passes them to the next dog it bites. Those babies take about six months to grow up, which is why a dog can look and act completely normal for a long time before a test turns positive.

Central Illinois gives mosquitoes plenty to love, from the Illinois River bottoms to backyard birdbaths and the occasional forgotten kiddie pool. Our warm springs and long falls stretch mosquito season out, and a sunny October afternoon is no promise they’ve packed up for the year. That’s why we recommend heartworm prevention every single month, all year long, and a heartworm test once a year for every dog.

Your Dog Tested Positive. Now What?

First, we double-check. The American Heartworm Society recommends confirming every positive result with a second, different test before starting treatment, and we do exactly that. Once it’s confirmed, we take a closer look at how the worms are affecting your dog so we can build a plan that fits them.

That checkup usually includes:

• A confirmation test to make sure the result is real
• A blood test for baby heartworms circulating in the bloodstream
• Chest X-rays to see how the heart and lungs are holding up
• Bloodwork and a urine test to make sure your dog’s body is ready for treatment

If your dog is coughing, tired, or breathing hard, we’ll get them comfortable and stable first. Treatment goes much more smoothly when a dog starts from a good place.

The best thing you can do on day one? Start (or keep giving) monthly heartworm prevention. It stops new worms from moving in while we deal with the ones already there.

How Heartworm Treatment Works, Step by Step

We follow the treatment plan recommended by the American Heartworm Society, which is the gold standard for clearing heartworms safely. It takes a few months, because getting rid of the worms slowly and carefully is much easier on your dog than doing it all at once. Your veterinarian will fine-tune the timing for your pup, and it generally looks like this:

1. Monthly prevention starts right away to clear out young worms and keep new ones from settling in.
2. About a month of an antibiotic called doxycycline. Heartworms carry a bacteria that causes a lot of the inflammation when they die, so knocking it out first weakens the worms and makes treatment gentler.
3. A month of rest so the body can settle before the main event.
4. The first injection. Melarsomine is the only FDA-approved medication that kills adult heartworms. It’s given in the back muscles, and your dog spends the day with us so we can keep a close, caring eye on them. Most dogs head home with medication for inflammation and soreness.
5. Another month of rest.
6. Two more injections, 24 hours apart, to finish off the remaining worms in a way that’s easier on the heart and lungs.
7. A blood test about a month later to make sure the baby heartworms are gone.
8. A final heartworm test nine months after the last injection to confirm your dog is in the clear.

It’s a commitment, and you won’t be doing it alone. We’re here for every appointment, every phone call, and every “is this normal?” text along the way.

The Hardest Part: Keeping Your Dog Calm

Rest is the most important thing you’ll do during treatment. As the worms die, they break apart and travel into the lungs, where the body slowly clears them. A racing heart and heavy panting can push those pieces where they cause trouble, including dangerous blockages in the lungs.

The American Heartworm Society recommends limiting activity through the whole treatment period and for at least six to eight weeks after the last injection. In real life, that looks like:

• Short, slow leash walks, just long enough for potty breaks
• No running, fetch, zoomies, dog parks, or wrestling with the family cat
• A crate or a small, quiet room when you can’t supervise
• Calm hellos at the door (easier said than done, we know)

Asking a young Lab to take it easy for a few months is a bit like asking a kindergartner to sit still at a birthday party. Food puzzles, lick mats, frozen stuffed Kongs, gentle sniffing games, and simple training tricks can tire out the brain without revving up the heart. If your dog is really struggling to settle, give us a call. Calming medication is a safe, common part of heartworm treatment, and it can make the whole process easier on everyone in the house.

Call us right away if you notice a cough that’s getting worse, trouble breathing, coughing up blood, weakness, collapse, pale gums, or a fever.

Life After Heartworm

Once your dog passes that final test, they can slowly get back to their favorite things. We’ll help you build back up gradually, the same way you’d ease back into running after some time off. Dogs who had more advanced disease may have lasting changes in the heart or lungs, and we’ll talk with you about any ongoing care they might need.

From here, the goal is to make sure this never happens again. Treatment is long, uncomfortable for your dog, and costs many times more than a year of prevention. A monthly preventive given without gaps, plus a heartworm test every year, is the simplest way to keep your pup safe. Our puppy wellness memberships include a heartworm test, and our Gold plans include six months of prevention, which makes staying on track one less thing to remember.

Here for Dogs in Peoria, Dunlap, and Kickapoo

Prairie Animal Hospital is right here in Peoria, an easy drive from Dunlap and Kickapoo. Whether your dog just tested positive or you’d like to get them started on prevention, call us or request an appointment online. Our Fear Free Certified team will walk you through every step with patience, kindness, and plenty of treats.