How Do Dogs Get Heartworm Disease?

Did you know that just one bite from an infected mosquito can jeopardize your dog's health? It's true — that one simple act can transmit potentially fatal heartworm disease to your canine family members. Staying informed about what causes heartworm disease in dogs, as well as heartworm symptoms and treatment, is key to heartworm prevention.

What Is Heartworm in Dogs?

Heartworms are spaghetti-like worms that make their way into the major blood vessels of a dog's lungs and heart and begin to reproduce. Left untreated, the heartworm larvae will mature into adult heartworms and can pose a serious health threat to your pet.

How Do Dogs Get Heartworm?

Mosquitos are often the cause of summer itchiness, but they are also the primary cause of heartworm in dogs, cats, foxes, wolves, ferrets and (rarely) humans. When mosquitos take blood from an animal infected with heartworm, they are also drinking in microscopic baby heartworms. When they land on a pup and take a bite, those tiny worms are injected into a dog's bloodstream and can result in an infected dog or puppy.

Is There a Vaccine for Heartworm in Dogs?

There is no vaccine for heartworm in dogs, but there are many preventative options, including:

1. Regular, year-round checkups with your vet
2. Administering heartworm prevention medication (usually chewable)
3. Keeping mosquitos out of your house
4. Minimize bugs in your outdoor spaces (with pet-friendly products)

What Are the Symptoms of Heartworm Disease in Dogs?

If your dog has a worsening cough and seems to be getting tired easily, it could be a sign of heartworm. However, some infected dogs may not show symptoms until the condition has worsened. Other signs of heartworm in dogs may include:

• Persistent coughing
• Reluctance to exercise
• Tiredness
• Decreased appetite
• Weight loss

To diagnose the disease, a blood test for heartworm, or heartworm test, should be performed at a veterinary hospital.

Will Heartworm Shorten My Dog's Life?

According to the American Heartworm Society, if left untreated, heartworm can cause breathing problems and even lead to heart failure (which can shorten a dog's life.) The good news is that in many cases (though not all) early treatment can help reduce the symptoms a dog experiences, so talk to your vet.

The even better news? Heartworm is preventable.

Can My Dog Recover From Heartworm?

Heartworm treatment and recovery depends on many factors, including your dog's health, age, breed and lifestyle. However, once your dog has acquired heartworm, they will need special care and treatment, likely including injections of medication, antibiotics, exercise restriction and, in severe cases, surgery.

If you think your dog could have heartworm, or you've never asked your vet about it, don't hesitate to reach out to them. Your veterinarian is the best person to discuss both heartworm preventive and treatment products with, and which are the best fit for your dog.

How Much Does It Cost to Treat Once My Dog Has Heartworm?

Benjamin Franklin once said an ounce of prevention is worth a pound of cure. When it comes to heartworm in our canine companions, this is especially true. Heartworm treatment can cost up to $1,000 (vs an average of $120 per year for prevention methods).¹

In addition, catching heartworm early translates into savings both for your wallet and your dog's health. That means it's important to stay current on your dog's yearly exams and to ask your veterinarian about heartworm prevention.

CareCredit Credit Card Financing for Dogs

The CareCredit credit card provides a convenient way to pay for your dog's vaccinations and other health and wellness expenses, including exams, medications and products at providers in the CareCredit network.* Apply today and continue your wellness journey by downloading the CareCredit Mobile App. You can find a provider on the go, manage your CareCredit account and easily access the Well U hub for more great articles, podcasts and videos. Use our Acceptance Locator to find a veterinarian that accepts CareCredit to help keep your pet healthy and happy for a lifetime of love.

Expert Reviewer

Dr. Karen Halligan, D.V.M.

Dr. Karen "Doc" Halligan earned her Doctor of Veterinary Medicine (D.V.M.) from the University of California, Davis. After completing her formal education, driven by her love for animals and a desire to enhance the human-animal bond, she has worked tirelessly to provide exceptional care for pets and educate pet owners on responsible pet ownership.

She is the author of the award-winning book Doc Halligan's What Every Pet Owner Should Know: Prescriptions for Happy, Healthy Cats and Dogs and has authored countless articles for various magazines and other media. She has appeared on numerous television shows, including "The Doctors" and "Animal Planet," where she has shared her knowledge and provided expert advice on various animal health topics. Her ability to communicate complex veterinary concepts in an accessible manner has made her a sought-after speaker.

She currently practices general medicine and surgery at Marina Veterinary Center in Westchester, CA.

Author Bio

Kristin Driver is a Digital Writer with Synchrony. She specializes in writing about health care, finances and pet care. Her work has been published by Cedars-Sinai, UCLA Health, Stanford Health Care, Risk & Insurance, Modern Health Care, Risk Insider, CIO Review and more.