Heartworm Testing 1-2-3


Pet owners headed to the veterinary office this spring for their pet’s annual or semi-annual check-up are likely to hear these words from their veterinarian: “Your pet needs a heartworm test.” Testing, along with prevention, is an important part of keeping our dogs and cats healthy and free of heartworm disease. Here are important facts to know about heartworm disease and heartworm testing.

1. Why should I have my pet tested for heartworm?

Heartworm disease is a serious, progressive disease. The earlier it’s detected, the easier it is to treat.

A veterinarian cannot diagnose heartworm disease from an examination alone. There may be few, if any, signs of disease when a dog or cat is infected with heartworms, so detecting their presence with a heartworm test is vital.

2. What is a heartworm test?

  • A heartworm test is a simple blood test that requires only a small sample from your pet.

If your pet tests positive for heartworm, further tests may be ordered.

3. How often should my pet be tested for heartworm?

  • Yearly testing is the standard of care for dogs and is recommended by the American Heartworm Society.

If a dog or cat is showing signs of heartworm disease, such as coughing or stress during exercise, your veterinarian may order a test.

Your veterinarian will also test your pet before prescribing heartworm medication for the first time.

4. Does my dog need an annual heartworm test if I’m giving him a heartworm preventive year-round?

The American Heartworm Society recommends year-round protection from heartworm disease for both dogs and cats.

Annual testing for dogs is also recommended to ensure dogs are free of heartworm before renewing an annual prescription. While preventive medication is highly effective, pets can become infected if a dose is missed, a heartworm pill is vomited or spit out, or in the case of topical medications, is incorrectly applied.

If a dog infected with heartworms is given heartworm preventive, it can become very ill. Annual testing can help your veterinarian detect an infection as soon as possible, which makes it easier to treat.

If you have additional questions about heartworm testing, ask your veterinarian or visit heartwormsociety.org.