Preventing heartworm disease in dogs

When it comes to heartworm disease, prevention with heartworm medicine for dogs is the best plan of attack.

Heartworm disease has been reported in every U.S. state1. In fact, the American Heartworm Society estimates that more than 1 million dogs currently have heartworm disease.


Heartworm is caused by mosquitoes biting and infecting dogs with this potentially deadly disease. While your dog is at higher risk in summer months, you should provide year-round treatment with a broad-spectrum parasite preventive product without interruption, regardless of where you live.2,3

Why your dog needs a year-round heartworm disease preventive

Don’t assume that cold winter weather eliminates the threat of heartworm disease in dogs. Starting and stopping heartworm medicine based on seasonality can cause gaps in your dog’s protection and leave them vulnerable to infection. But you can reduce this risk by protecting your dog from heartworm disease year-round.

However, if your dog has less than year-round heartworm prevention, it’s important to administer a heartworm prevention medicine like Interceptor® Plus (milbemycin oxime/praziquantel) for at least 6 months after your dog’s last exposure to mosquitoes.

It can take up to 6 months or longer for the signs of heartworm infection to manifest in your dog, and some dogs may display no signs at all.

Two vital steps to prevent your dog from developing heartworm disease

  1. 1.Annual heartworm testing: Ask your veterinarian about testing your dog annually for a heartworm infection. If the test comes back positive, your veterinarian will discuss treatment options for your dog.
  2. 2. Year-round heartworm prevention:Give your dog the year-round heartworm protection of Interceptor® Plus (milbemycin oxime/praziquantel). It’s as easy as one chewable tablet every month, and then you’re set for year-round heartworm disease prevention. If your veterinarian prescribes less than year-round prevention, it’s important to administer Interceptor Plus for at least 6 months after your dog’s last exposure to mosquitoes.

You might be interested in…

Want to keep reading? Learn more about worms by exploring the articles below.

Heartworm lifecycle

Learn how your dog gets infected with heartworms and how they develop in the body.

Signs of intestinal worms

See which signs you should be looking out for so you can recognize potential intestinal worms.

Why Interceptor Plus?

Find out how monthly Interceptor Plus provides effective, year-round heartworm disease prevention.


Interceptor Plus prevents heartworm disease and treats and controls adult roundworm, hookworm, whipworm, and tapeworm infections in dogs and puppies 6 weeks or older and 2 pounds or greater.

Important Safety Information

Treatment with fewer than 6 monthly doses after the last exposure to mosquitoes may not provide complete heartworm prevention. Prior to administration of Interceptor Plus, dogs should be tested for existing heartworm infections. The safety of Interceptor Plus has not been evaluated in dogs used for breeding or in lactating females. The following adverse reactions have been reported in dogs after administration of milbemycin oxime or praziquantel: vomiting, diarrhea, decreased activity, incoordination, weight loss, convulsions, weakness, and salivation. For complete safety information, please see Interceptor Plus product label or ask your veterinarian.

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