Frequently asked questions

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 in the mosquito and then are transmitted to another dog when that dog is bitten by the infective 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 lung damage and potentially 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 helps prevent 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 blood stream.

HEARTGARD Plus is safe and effective in any breed of dog when used as directed.

IMPORTANT SAFETY INFORMATION:

HEARTGARD Plus (ivermectin/pyrantel) 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.

No, the way dogs become infected is via a bite from a mosquito that is infected with 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.

Prevention is best

When it comes to heartworm disease, prevention is the most effective treatment.

Find a vet near you

The heartworm protection you need is only available with a vet’s prescription.

IMPORTANT SAFETY INFORMATION:

HEARTGARD Plus (ivermectin/pyrantel) 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.