Tuesday, April 9, 2013

A-Z Challenge: H is for Heartworms

Welcome to the A-Z Challenge! This year my theme is Pet Health - information for people about their furry, four-legged family members.

Heartworm disease in dogs and cats is seen in all 50 US states, the first case was in 1847 on the east coast. Since then, it has spread throughout the country. It's easily preventable. It's treatable but very expensive and your dog must be kept quiet for several weeks. If anyone has ever tried to keep a dog "quiet" for any length of time, you know it's a challenge.

But while it's easily preventable, many dogs (and even cats) wind up testing positive for heartworms. Because while it's easy to prevent, people often balk at the price tag on the box of prevention from their veterinarians.

Heartworm disease is spread via mosquitoes. A mosquito bites a dog that has adult heartworms that lay larvae that enter the bloodstream and sucks up the larvae. The mosquito is required for the next stage of growth for the larvae. When this infected mosquito bites an uninfected dog (or cat), the larvae enters the animals skin.  The heartworm larvae continue to mature and develop, migrating through the tissues and reaching the heart and pulmonary arteries. Larvae become adult heartworms within 6 months of infection. 

Symptoms of heartworm disease include: coughing, lethargy, exercise intolerance, weight loss, and decreased appetite. Make note that these symptoms will not occur right away and it's best to not wait until symptoms show before you take your pet to the veterinarian.

The role of heartworm prevention is thus: all our dogs and cats are constantly exposed to heartworms (check with your veterinarian if you live in a high risk area), and the prevention kills the larvae they are exposed to. If you miss a dose, that's when your pet can become infected. Once the larvae reach a certain stage, prevention will no longer be of any real use. Heartworm testing should be a regular part of your pets prevention. If you have missed a dose, don't automatically bring your pet in for a heartworm test. The test your veterinarian does in house typically only tests for the presence of adult heatworms, not the larvae. If you have missed a dose, it's best to wait 4-6 months to bring your pet in for testing. You can continue to give the prevention every month until testing.

A lot of people ask (sometimes rather indignantly) why many vet clinics either require or recommend annual heartworm testing as a part of the prevention. People say, "Well, I give Fido their pill every month, why do I have to have a heart worm test every year? Are you telling me I'm spending money on something that doesn't work?" No, you're not throwing away your money. Trust me. However, in rare cases, your pet may contract heartworms while on prevention - but it is rare. Also, if you miss a dose (and most people do not want to admit they've done so), it's wise to have your pet tested (about 4-6 months after the missed dose). However, it's good to know that Merial, the company that makes Heartgard, will pay for your pet's treatment for heartworm disease. Know that you will need to show proof that you've been buying the product, and have a record of negative testing and I believe two positive tests.  Ask your veterinarian for details. 

Another thing owners often say is, "My pet is strictly indoors. It's not exposed." Bull honkey. You probably take your pet outside to use the potty. And if you don't . . . I'm pretty sure mosquitoes get in your house. Because no matter how hard I try, I always wind up with a mosquito in my house. So even your house cat can get heartworms. But I can't force you to buy prevention, nor get a heartworm test.

If your dog tests positive for heartworms, there is treatment, although here's fair warning, it's expensive. The price for treatment can vary depending on how bad the infestation is, how many doses the pet missed, or if it had ever been on prevention. If the veterinarian believes they caught it pretty early and your dog (or cat) is showing no physical symptoms of the disease, treatment will (hopefully) be cheaper. However, be aware that treatment can run you roughly $1000, if not more. Also, your pet will need to be kept quiet for a few months during treatment. They are treated with a poison to slowly kill off the worms, and excess activity can cause harm.

Heartworm prevention can look pretty spendy, too, when you're paying for it at the vet's office. In my area, Heartgard Plus runs anywhere from $45-$90 (average) for a 1 year supply of each weight category. Break it down month by month and really, it's not that expensive compared to paying $1000 to treat your dog for the disease and be forced to keep your pet quiet/confined for a few months. Especially when you take into consideration that it is rare for any vet office to allow payment plans, so you have to typically pay for everything up front.

There are several types of heartworm prevention options out there. The type of prevention you choose will depend on you and your pet's lifestyle and the area that you live. There are two types - oral or topical; some do just heartworms, some do heartworms plus other internal parasites, and still others do that plus fleas and in some cases, ticks.

(Click any prevention for a side by side comparison)

Another tip: Veterinary clinics often get "puppy/kitten packs" from their representatives, where you can get free samples of heartworm and flea prevention. Most often the doctors may only give these out if you've purchased a "puppy/kitten vaccine package", but if you ask they may go ahead and give you the samples, especially if they get more than they can give away (believe me I've witnessed that some clinics get tons!).

Another tip: Ask your veterinarian or their staff if there are any rebates on heartworm prevention available - clinics often get coupons or rebates from their representatives. Also, ask if they are offering free heartworm tests with an exam or vaccination visit, or even if you purchase heartworm prevention. Exam fees will vary greatly, but in general don't expect to pay much less than $40 for the exam, if you get a free heartworm test with that (or vaccines or buying prevention), it's probably a minimum $30 item.

My sources: Pet Health Network, Pet Education by Dr.'s Foster & Smith, plus my own experience working in large/small animal practice as well as a veterinary laboratory.


  1. Great reminder. They ARE expensive... I didn't know how they spread, so that's a good piece of info, too. Dumb mosquitoes. But we definitely have enough to be careful. We love our pets.

    1. Thanks for stopping by! Mosquitoes can help carry lots of things. Stupid little bloodsuckers. lol

  2. Scrappy gets his faithfully, and it works if lack of "exercise intolerance" and "weight loss" mean anything.

  3. Some owners seem to have the same attitude regarding Parvo. And have a fit when told the cost of the treatment - when having the vaccinations would have been far cheaper in the first place.

    At least with heartworm, I don't have to bleach down every surface in the clinic...

    1. Oh yes, I completely agree!! And bleaching the clinic is just terrible. At Sticksville, there were days I bleached the front lobby so many times I smelled of bleach for days afterward, which only made me ill. Ick!!

  4. EXCELLENT post!! Great reminder. I know my Gracie is like my 4th baby!
    Peanut Butter and Whine

    1. Thank you! And thanks for stopping by! Much appreciated!

  5. Indeed! Heartworm medication is so important for our 4 legged friends. Its probably the reason my old dog lived 16 good years. ;)


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