Humane Society of Central Illinois


Heartworms are now becoming a increasing problem. Years ago, dogs were not checked nor treated for heartworms because at that time the disease was not as great a threat as it is today.

Now, it is more urgent than ever to check your dog for heartworms. Heartworms are transmitted by mosquitoes. If a mosquito were to bite a dog with heartworms and then bite your dog, your dog would then be infected with this lethal parasite. Do not be fooled into thinking that long haired dogs are at low risk! Mosquitoes can bite areas near the eyes, nose, and also the rectum. Inside dogs are also at risk because your dog still needs to go outside to eliminate. Mosquitoes may also travel into your home through an open door or window.

Some of the symptoms of heartworm disease are:

  1. Cough
  2. Shortness of breath
  3. Tires easily upon exercise

The disease, if untreated, is fatal to its victim. This is why it is so important to have your dog tested for heartworms every year. The test involves taking a simple blood sample. The sample is then examined under the microscope to see if microflaria -- baby heartworms -- are present. If microflaria are present in the sample, treatment should begin as soon as possible.

Treatment begins by taking another blood sample to see if your dog would be able to withstand the treatment. The treatment involves a series of arsenical compound injections. This is the only treatment approved at this time.

The good news is that there is a way to prevent your dog from getting this deadly disease. The preventative is available in many forms. The most convenient and most popular preventative of dog owners is a once-a-month tablet. This method of prevention involves giving a tablet just once a month. The medication is available in a tablet or chewable (treat) form. Of course, the old standby of a daily tablet is still available. The preventative, regardless of method, is an inexpensive and effective way to help prevent your dog from getting heartworms.

Commonly Asked Questions About Heartworms

Aren't heartworms only in the warmer states?

No, where there are mosquitoes, there are heartworms.

Since my dog was on preventive last year, does he still need to be checked?

Yes, testing is the only way of checking to see if your dog is negative and that he stays that way.

If I put my dog on preventative, do I have to force a pill down his throat every day?

No, because there are several types of preventative available. There is a preventative in which a tablet or chewable treat may be given only once a month. However, the daily form is still available.

Can a dog used for breeding be placed on a preventative?

Yes, with no problems.

Do all dogs need to be tested and placed on a preventative?

Yes, it is recommended that all dogs be tested and placed on a preventative. It is the only way to prevent heartworms in your pet.

What if I were to give the preventative without testing my dog?

If your dog were to have heartworms and the preventative was given, your pet would have a severe allergic reaction, may cause shock-like symptoms, and even possible death.

Can my dog get heartworms by being around a dog with heartworms?

No, not unless a mosquito bites the infected dog and then bites your dog.

My dog never goes outside. Does he still need to be tested and then placed on a preventative?

Yes, most dogs go outside to do their business. Also, it is still possible for mosquitoes to come inside your home through an open door or window.

Prepared for Highland Hospital for Animals by Vicki Carter, C.V.T.