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With the change in seasons comes warmer weather and longer days. Unfortunately, pesky bugs also come out. Critters are not only irritating for your dog but they can be very harmful too. In fact, the deadly parasite heartworm is transmitted only by mosquitos. Here are a few tips to keep your dog safe:

1. Preventative Medicine

The American Heartworm Society and many veterinarians recommend year-round preventative medication due to heartworm being found in all 50 states.

While the prevalence of heartworm historically has been high in the South, the American Heartworm Society reports that it’s on the rise throughout the U.S. This increase includes regions that were once considered “non-endemic.” Even if you don’t live in an area where heartworm is prominent, you still want to talk to your veterinarian about preventative medication for your dog.

There are a variety of preventative products that you can use on your dog to ward off mosquitos and prevent heartworm. These products can be administered orally or topically, and prevention is far more effective and less costly than treatment if your dog is diagnosed with heartworm. But, remember that preventives are not used to kill the adult worm and some can cause severe problems if given to animals with adult heartworms. You should follow the recommendations of your veterinarian prior to giving the preventive product.

Australian Cattle Dog laying down in the grass.
©Tanya -

2. Routine Veterinarian Visits

Schedule your dog for an annual checkup. Performing routine heartworm testing is usually included in this checkup and is the first line of defense for keeping your dog safe.

Heartworm preventative medication can only be obtained from a veterinarian or with a veterinarian’s prescription through a pet pharmacy, so start the conversation early. Talk to your veterinarian about which preventative is right for you and your dog.

Again, certain preventatives can protect against other parasites such as roundworms, hookworms, fleas, and tapeworms. Your veterinarian will know the differences between the types of preventatives and can help you choose the right one.

The recommendation from the American Heartworm Society is to have all dogs tested for heartworm every 12 months, even those already on heartworm preventative medication.

3. Keep Your Home & Yard Mosquito Free

It may not be top of mind, but mosquitos can also be a threat in and around your own home. Mosquitoes can breed in small amounts of stagnant water, which can be found in flowerpots, empty containers left outside (buckets, toys), rain gutters, and low-lying areas in the yard.

Mosquitoes all across the country can carry heartworm, which means one bite from an infected mosquito can result in heartworm disease in your dog. There is no way to know whether a mosquito is infected, and it often takes several months for heartworm symptoms to appear in dogs. In my years as a veterinarian, I have treated many dogs after they have contracted the disease and sadly some cases were too advanced for treatment to be successful.

Minimizing bugs in your yard is very important in helping to keep bugs away from your dog. You may want to consider using insecticide spray for your yard, but be sure you chose a pet-friendly product and you follow the manufacturer’s instructions properly. In addition to yard treatments, there are many other forms of mosquito repellent.

Boykin Spaniel puppy sitting in tall grasses looking up.

4. Keep the Routine Each Year

Heartworm disease can cause lasting damage to the heart, which can affect a dog’s health and quality of life — just one of many reasons to have your dog on preventative medication.

Heartworms mature after six months and can live in your dog’s body for seven years, constantly producing offspring. After about a year, a dog may harbor hundreds of these worms, although the average is 15. The worms cause inflammation and damage to the heart, arteries, and lungs.

The recommendation from the American Heartworm Society is to have all dogs tested for heartworm every 12 months, even those already on heartworm preventative medication.

Have your veterinarian test your dog for heartworm during your annual visit.

What Else to Know About Heartworms:

  • Heartworm disease (Dirofilaria immitis) affects the heart and arteries surrounding the lungs and is caused by parasitic worms that can grow up to one foot long. If left untreated, the damage to the heart and lungs can be deadly.
  • Heartworms are only transmitted through the bite of an infected mosquito and are not transferred from pet-to-pet or to or from humans.
  • Once infected with the heartworm larvae, it can take several months for symptoms to appear in your pet as the worms grow and impact the organs.
  • While reported cases vary state to state, Heartworm infected mosquitoes and cases of the disease have been reported in all 50 states.
  • The most common symptoms of heartworm disease are: exercise intolerance, coughing, lethargy, changes in appetite and body conditioning. Watch for these symptoms but do not self-diagnose – only your veterinarian can test and diagnose.
  • Heartworm does not discriminate – all dog breed types are susceptible.
  • If found early, this is a treatable illness. In later stages, however, treatment is difficult and may be impossible, in which case your vet will guide you in making the best decisions for your pet’s comfort.
  • It is recommended to have your dogs on year-round monthly or semi-annual oral prescription treatment. It is affordable and easy to administer with flavored edible chews or topical solutions. Ask your veterinarian what option is best for your dog.

Now that you are aware of heartworm and the dangers it poses to your dog, speak with your veterinarian today to keep your dog healthy, active, and heartworm-free!

This article is intended solely as general guidance, and does not constitute health or other professional advice. Individual situations and applicable laws vary by jurisdiction, and you are encouraged to obtain appropriate advice from qualified professionals in the applicable jurisdictions. We make no representations or warranties concerning any course of action taken by any person following or otherwise using the information offered or provided in this article, including any such information associated with and provided in connection with third-party products, and we will not be liable for any direct, indirect, consequential, special, exemplary or other damages that may result, including but not limited to economic loss, injury, illness or death.

Related article: What Do Flea Bites Look Like on Dogs?
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