What You Need to Know About Heartworm Prevention

Heartworm infection has been found in dogs in all 50 states

With spring and warmer weather just around the corner, many pet guardians start thinking of protecting their pets from fleas, ticks as well as heartworm disease. However, according to the Companion Animal Parasite Council (CAPC), “…heartworm infections continue to increase in numbers and geographic distribution.” While the greatest number of cases are seen in the southeastern US, heartworm infection has been found in dogs in all 50 states. Treating heartworm disease in dogs can be difficult and expensive, and although cats are less susceptible than dogs to heartworm disease there is no approved treatment for heartworm infection in cats. The American Heartworm Society recommends year round heartworm prevention and annual testing for your pets.

What is heartworm disease?

Heartworm disease is a potentially fatal condition caused by parasitic worms that live in the arteries, heart, and lungs of dogs and cats of any age. Heartworm is transferred from pet to pet by infected mosquitoes. When a mosquito that is carrying the infective larval stage of the heartworm bites your pet, your pet can become infected. Once infected the heartworms multiply and take up residence in your pet’s heart, arteries and lungs destroying them over time.

How can I protect my pet from heartworms?

There are two types of heartworm prevention products on the market today: oral chewable tablets such as Heartgard Plus or Iverhart Max, and topical solutions such as Revolution or Advantage Multi which is applied to the skin of the pet. No one form is preferred over the other. Before starting your pet on a preventative heartworm medication, your vet should test your pet for heartworm. It can be very harmful to your pet if preventative medication is started if your pet is already infected with adult heartworms. In addition, your pet should be tested annually for heartworm as it is easy to forget and miss a dose of the medication. It is important that your pet be protected year round because the American Heartworm Society (AHS) keeps track of how and when heartworm is diagnosed and they have determined even in cold or dry climates heartworm is found year-round.

Administration is very simple with both topical and oral medications but there are a few instructions to each that must be followed for optimal pet protection. For the oral formulation, be sure that your pet chews and swallows the medication or you may break it up and feed it to them in a small amount of food. Never split doses between pets, and do not split the dose in half. For example do not give half every two weeks but rather, give one full dose every 30 days. For the topical medication apply 1 entire applicator tube every 30 days. To apply the medication open the tube, apply to the skin at base of the neck while parting the hair aside. Squeeze the tube 3 or 4 times and be sure all of the medication is out of the tube and applied to the skin of your pet. Always consult your veterinarian or veterinary pharmacist if you have any questions about administering heartworm prevention.

Heartworm is a very real threat to your pet but prevention is very easy and convenient. Always talk with your veterinarian to make sure which heartworm prevention is right for your pet. With the right medication and the correct administration technique, heartworm should no longer be a concern.

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  1. A rescued Cocker that I have had for 2 yrs. has hot spots from time to time, not sure what the cause is. She is currently on Revolution flea treatment, and the directions say not to use if pet is ill. She is a couple of weeks overdue for the Revolution treatment but still has the hot spot on the inside of her back leg although it is almost gone. Should I wait until the hot spot is gone completely before using the Revolution? This will be her last treatment, since I don’t use Revolution in the winter since there are no mosquitoes. Thanks in advance.

  2. Dr. Michael Dym, VMD veterinarianNovember 26, 2014 at 12:39 am

    I dont think using revolution if dog has a hot spot is a problem. I would go ahead and use it.

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