FDA: An Ounce of Prevention is Worth a Pound of Cure. 　

Emergency Message System

October 27th, 2023

Heartworms can infect your pet year-round and preventing them is much easier, and healthier, for your pet than getting heartworms in the first place or treating heartworm disease afterward. Year-round prevention is key to keeping your pet heartworm free.

What are heartworms and how do pets get them
Heartworms are parasitic worms spread by infected mosquitoes. The parasites can cause severe disease and even death in dogs, cats, and other species of mammals, including ferrets.

The heartworm larvae enter the pet’s body through the mosquito bite and then move into the bloodstream, eventually infecting the animal’s heart and lung arteries and growing up to 12-inches long.

The disease is not contagious from one pet to another, and heartworms in people are very rare.

Early signs of heartworm disease in pets are subtle and can be missed. As the disease progresses, pets may have a persistent cough, tiredness after mild to moderate activity, trouble breathing, and a decreased appetite. If left untreated, heartworm disease will damage the animal’s heart, lungs, liver, and kidneys, eventually causing death.

Use heartworm prevention medication year-round
Although there are fewer mosquitoes in the winter, there is still a risk that your pet could get heartworms if you stop giving heartworm prevention medication during this season. That’s one reason veterinarians strongly recommend pets receive heartworm prevention medication year-round.

Veterinarians have reported heartworm disease in pets in all 50 states. Living in a state with a colder climate doesn’t mean that your pet is safe. Pets must have the proper amount of heartworm prevention medication in their blood for it to work correctly. If mosquitoes emerge early in the year, pets that haven’t received heartworm prevention medication during the winter run the risk of getting heartworms.

Dogs: Testing for heartworms is important
Be sure to ask your veterinarian to test your dog before starting or restarting a heartworm prevention medication. Dogs that have heartworms may not show symptoms right away, and your veterinarian can test your dog with a simple blood test.

Keeping your dog on heartworm prevention medication year-round, combined with annual testing, helps ensure any infection is caught promptly, thus minimizing harm to your dog from the infection.

If your dog becomes infected when he or she is not on a heartworm prevention medication and you later resume giving the medication without first testing your dog for heartworms, you may be putting him or her in danger.

Also, heartworm prevention medication will not kill adult heartworms, which will continue to reproduce. When a non-infected mosquito bites a heartworm-infected dog, the can mosquito become infected and can pass on heartworm larvae when it bites another unprotected dog, continuing the heartworm disease cycle.