Important Safety Infomation

Important Safety Information

HEARTGARD Plus is well tolerated. All dogs should be tested for heartworm infection before starting a preventive program. Following the use of HEARTGARD Plus, digestive and neurological side effects have rarely been reported. For more information, contact your veterinarian or click here for full prescribing information.

Help Protect Your Dog
from potentially deadly Heartworm Disease with HEARTGARD® Plus.

You can't stop mosquito bites. But with HEARTGARD® Plus, you can kill the heartworm larvae that are transmitted to your dog by those annoying bloodsuckers, preventing heartworm disease.

Takes the Sting Out of

heartworm disease

  • Heartworm disease is in all 50 states
  • Prevents heartworm disease in your dog
  • Kills heartworm larvae, roundworms, and hookworms
  • Easy-to-give—most dogs eat it right out of your hand
  • Give one each month, year-round
  • Helps avoid the cost of treating heartworm disease, and the risk of possible death from heartworm disease
  • Available by prescription from a veterinarian—annual testing for heartworm disease is recommended

All in a delicious real-beef chew
that dogs love



It's the
#1 Choice of Vets1

for heartworm disease prevention

HEARTGARD Plus is the most recommended heartworm disease preventive for dogs.1 Ask your vet about heartworm testing and the importance of year-round use.

For use in dogs only.

Up to 25 pounds

26 to 50 pounds

51 to 100 pounds


One Mosquito

is all it takes to transmit heartworms to your dog

Heartworm larvae are transmitted by infected mosquitoes. When the infected mosquito bites, the larvae pass through the tissue into the bloodstream. 70 days later they reach the arteries of the lungs where they continue to develop and grow.

Once they arrive in the lungs, at 70 days post-infection, they can start to do damage.

What exactly is

Heartworm Disease?

  • Heartworm disease is a serious and potentially fatal condition in dogs
  • It is caused by worms that spend their adult lives on the right side of the heart and the large blood vessels that connect the heart to the lungs
  • It is transmitted through infected mosquito bites
  • Dogs of all ages are susceptible to infection
  • Signs range from no sign at all to persistent cough, fatigue, fainting and weight loss
  • Heartworm disease is usually detected with a blood test
  • Treatment is an expense for the owner, and a painful, prolonged ordeal for the dog
  • Prevention of heartworm disease is recommended versus heartworm disease treatment

Year-Round Prevention

is recommended

If your dog tests positive for heartworm, treatment can be risky, expensive, and often involves hospitalization. Prevention of heartworm disease is highly recommended.

HEARTGARD® Plus Chewables are proven effective to prevent heartworm disease and are made with real beef that dogs love.2 Ask your vet about them to learn more.

Left untreated, the heartworm
larvae can continue to

Grow and Grow

After entering into the tissue, th​e heartworm life cycle begins with the presence of infected larvae. Once larvae arrive in the heart and lungs, they can cause damage as early as 70 days.

Adult worms can extend up to 12 inches long—creating serious damage.


Lock in Savings

Get $12 back when​ you buy
12 doses of HEARTGARD Plus

Receive a $12 rebate when you buy HEARTGARD Plus. Simply download a coupon, then take it to your vet. You'll soon receive your rebate in the mail.

Save $50

Purchase 12 doses of HEARTGARD Plus and 12 doses of any of our flea and tick control products from your vet and get $50 back.*

*Just print the coupon and present it to your vet when you make your purchase. Then mail it in to get your $50 rebate.

HEARTGARD® Plus comes with our
Plus customer satisfaction guarantee

If you’re not completely satisfied with HEARTGARD® Plus, you may be eligible for the Satisfaction Guarantee.


Find a Vet

to help prevent disease

HEARTGARD Plus is only available by prescription from a veterinarian. To find one in your area, simply complete the form below.


Questions & Answers

we're here to help

Heartworm disease in dogs (dirofilariasis) is a serious and potentially fatal disease. Heartworms spend their adult lives in the pulmonary arteries. The adult worms can cause lasting damage to the heart, lungs and arteries.
Heartworms are transmitted from one dog to another by mosquitoes, which pick up tiny immature heartworms, called microfilariae, when they bite an infected dog. Larvae develop and are then transmitted to another dog when that dog is bitten by the infected mosquito.
All dogs are at risk for heartworm disease, no matter where they live—heartworms don't discriminate based on geography. In the past, heartworm disease in the United States was primarily limited to the South and Southeast regions. However, it is now found in all 50 states, in Canada, and is spreading to new areas each year.2 The American Heartworm Society notes that uncared-for dogs and certain wildlife can be carriers of heartworms. Mosquitoes blown great distances by the wind and the transportation of infected pets to different geographic locations can all contribute to the spread of heartworm disease.2
Signs of heartworm disease can be subtle and difficult to detect until its later stages. As the disease progresses, signs begin to appear. Contact your veterinarian immediately if you notice coughing, difficulty breathing, sluggishness and less energy for exercise in your dog. Adult heartworms cause serious harm to your dog's heart, lungs and certain internal organs. Left untreated, heartworm disease can result in loss of consciousness and death.
The most common method for heartworm testing is for a veterinarian to collect a small blood sample from a dog and evaluate the sample using a specialized test kit to detect the presence of adult heartworms.
Pet owners can use HEARTGARD® Plus (ivermectin/pyrantel), the #1 veterinarian-recommended preventive on the market1 to help prevent heartworm disease. HEARTGARD® Plus kills tissue larval stages of heartworms, and prevents them from developing into adults and causing heartworm disease. In an unprotected dog, heartworm larvae mature into adults and ultimately migrate to the arteries of the lungs.
Monthly use of HEARTGARD® Plus is essential because it cannot be determined with certainty when the threat of mosquitoes has passed. Talk to your veterinarian for dose and regimen recommendations.
Although it is possible to treat heartworm disease if a dog becomes infected, it is difficult, expensive and risky, particularly in dogs that have begun to exhibit clinical signs of infection.
There are treatment options available to kill adult heartworms in dogs that have become infected. Treating dogs with heartworm disease starts with a thorough physical examination by the veterinarian. The veterinarian will then discuss treatment options with you. Typically, the dog is hospitalized during the treatment period. Because there is a risk of blood clots or worm debris blocking blood vessels from adult heartworm treatment, the dog must then remain quiet in close confinement for another 4 to 6 weeks after treatment. A second round of treatment may be required for some dogs. The veterinarian may also give your dog a treatment to rid it of the immature larvae that are circulating through the bloodstream.
HEARTGARD® Plus is safe and effective in any breed of dog when used as directed.
No, the way dogs become infected is via a bite from a mosquito that is carrying heartworm larvae.
No. Puppies that are nursing may become infected. HEARTGARD® Plus can be used in puppies as young as 6 weeks of age—and puppies benefit from the ability of HEARTGARD® Plus to treat and control roundworms and hookworms.