National Heartworm Awareness Month

April 01, 2023

April is National Heartworm Awareness Month, and, by protecting our dogs, we as pet parents can also protect ourselves from the heartache that can come from the loss of a canine companion–or the expensive and difficult treatment due to this preventable health issue.

Established in 1974, the American Heartworm Society strives to stop the spread of the disease through both the distribution of funds for heartworm research and the spread of the information to researchers, veterinarians and the public. This month-long pet awareness holiday helps shine the spotlight on the danger of heartworm season before the worst months: spring and summer.

What are heartworms?

Roundworms which embed themselves in a pet’s heart, lungs and/or blood vessels.

How do dogs get heartworms?

Through the bite of a mosquito, which transfers infective larvae from a previous canine host on to a new victim.

How long can a heartworm stay in a dog’s system?

A heartworm can live out its life cycle in an infected host, mating and creating many more heartworms during that period.

When can my dog contract heartworms?

Although more prevalent during the summer months, mosquitoes can transmit heartworms throughout the year.

Is my dog at risk for getting heartworms?

Although dogs are more likely to get heartworms if they live in states where warm, moist weather is the usual forecast, any pet in the US is vulnerable to the disease.

Is Your Dog at Risk of Heartworms?

Heartworm disease is a growing problem across the United States–and, if you think you are outside the danger zone, at least for part of the year, please think again. A warming climate means mosquito populations are often surviving longer into the winter.

A few years ago, Banfield Pet Hospital released a list of the states with the most cases of heartworm:

  1. Missouri
  2. Arkansas
  3. Louisiana
  4. Alabama
  5. South Carolina
  6. Georgia
  7. Oklahoma
  8. North Carolina
  9. Tennessee

But even if you’re not a resident of one of those states, you are not in the clear. An increasingly mobile population also means that dogs from heartworm-prone regions may bring heartworms into your region in many ways:

  • a new resident in your area may have relocated with a dog from a region with a high incidence of heartworms
  • a traveler with a dog with heartworms may introduce heartworms to your area
  • a dog rescued after a natural disaster like Hurricane Harvey may be relocated to another part of the country; puppies don’t test positive for heartworms until the worms mature.

Talk to your veterinarian about how to protect your dog from heartworms.

Can my indoor dog get heartworms?

As a warm home is a preferred place for the pest during the winter months, mosquitoes can easily infect a pet that does not venture outdoors.

What symptoms of infection should a pet parent look for?

While the early stage of the disease can be undetectable without a check up, pet guardians should watch for such developing symptoms as a nagging cough, disinterest in eating, weight loss, indifference to playtime and loss of energy.

How often should a dog be checked for heartworms?

A dog’s annual vet visit should include a test for heartworms, regardless of whether the dog regularly takes a heartworm preventative.

Through a series of infographics and videos, the organization arms animal lovers with the knowledge they need to combat this potential pet killer, such as:


Infographic Credit: American Heartworm Society

Can Your Dog Get Heartworms in the Winter?

We’ve talked before about the importance of maintaining your dog’s heartworm preventative all year, even during the winter months.

The danger that kind of mistake can put your dog in…along with the worry, guilt, and expense you can face for that kind of mistake…makes it vitally important that you keep that heartworm preventative going even when the weather cools.

Our Experience–in the winter!

Be sure to check with your vet to learn if you need to be giving heartworm preventative during the winter months. (Also, even though you might be hip deep in snow, if you and your dog will be traveling to a warm destination, check and see what you should do about heartworm preventative!) We live in Texas and have freezing nights and cool days–but still it’s warm enough to keep a mosquito population going year around.

And don’t think you’ll be saving money by skipping a dose. Even in today’s tight economy, that heartworm preventative is a great investment when compared with the cost of treatment (not to mention the cost to your dog’s health and the worry and guilt you’ll go through.)