Pet owners often don’t understand heartworm disease, its treatment, or how to prevent it, but they don’t always know the questions to ask. The following questions and answers about heartworm disease will help you keep your pet safe from this potentially deadly disease.

Why don’t people need heartworm preventives?

People can get heartworm disease if they are bitten by a heartworm-positive mosquito, but the human immune system recognizes and attacks parasitic worms quickly and efficiently. Even if the larvae get into the bloodstream, they rarely mature to adult worms. Since 1940, only about 80 cases of heartworm infection have been reported in humans. Keeping your pets on preventive medication will help lower your risk of infection and adding to that number.

Why does my dog need an annual heartworm test when she is on year-round preventive medication?

The American Heartworm Society researches heartworm disease and preventives and releases new recommendations and guidelines every three years. The organization’s most recent recommendations include screening all dogs at 7 months of age and then yearly, for the following reasons:

  • One missed or late preventive dose can leave your dog vulnerable to infection.
  • Heartworm disease cannot be detected for at least 6 months, so if your dog is heartworm-positive but is tested earlier than 6 months post-infection, a false negative result is possible.
  • The most common heartworm test, the antigen test, can show false negative results. The test results are based on the detection of protein secreted by adult female heartworms, so a pet with only a few females, immature worms, or male worms only, may show a false negative.

Do cats get heartworm disease?

Cats do get heartworm disease, but at a lower rate than dogs. One shelter study found that the infection rate in cats was only 5% to 15% that of dogs. Cats also have a different immune system that is more effective at eradicating  the heartworm larvae, called microfilariae. However, even a few worms can be life-threatening for cats because they can damage the heart and the surrounding blood vessels. In addition, when the worms die after 2 to 4 years, they can form an embolism that lodges in the lungs and is typically fatal.

Does my cat need heartworm preventive?

The American Heartworm Society recommends monthly preventive for cats who live in heartworm endemic areas, including indoor-only cats, who should always be treated because no home can be completely mosquito proof. One study found that approximately 25% of adult cats diagnosed with heartworm disease were considered indoor cats. Many heartworm preventives give cats extra protection because they also treat common intestinal parasites.

What heartworm preventives are recommended for dogs and cats?

Our hospital’s veterinarians have considered the multitude of products on the market and, for dogs, we recommend Sentinel and Sentinel Spectrum. Sentinel, a tasty chew given monthly, protects your dog not only from heartworms but also fleas, roundworms, hookworms, and whipworms. In addition, Sentinel Spectrum protects against tapeworms, is safe for puppies from 4 to 6 weeks old, and comes in four convenient dosing sizes.

For cats, we recommend Advantage Multi, a topical medication applied monthly that protects your kitty and eliminates the hassle of a pill. Advantage Multi treats fleas, ear mites, roundworms, and hookworms, as well as heartworms, and can be given to kittens at 9 weeks, as long as they weigh 2 pounds.

The Loving Family veterinary team wants what’s best for you and your furry companions. If you have more questions about heartworm disease, contact us. Our staff will be happy to help.