The Facts About Heartworm Disease

Heartworm Disease can be fatal. Heartworms in the right side of the heart stretch the chamber and cause heart failure or can lump together and lodge in the lungs where they can cause suffocation. Although Heartworm Disease is considered to be treatable, the treatment is nearly as bad for the dog as the disease itself. Because heartworm infections are preventable, we want you to understand the facts and prevent the disease. Always keep in mind Heartworm Disease is easily prevented, but difficult to cure.

Heartworm Disease is carried by an infected mosquito. When the mosquito bites the dog, it injects small worms under the skin. These worms migrate until they make their way into a blood vessel and begin circulating in the dog’s bloodstream. Over the next six months, worms will grow and change until they become adult worms. They make their permanent home in the right side of the heart where they breed and eject their young back into the blood stream.

Dogs are tested for Heartworm Disease by a simple yearly blood test. Since it takes six months from the time the mosquito bites the dog until the time we can detect it in our laboratory, when we take the blood test in the spring we are actually screening for infections from the previous summer. The type of test run depends on the preventative your dog is taking, daily or monthly.

Due to the rise in the number of infections in this area, we are currently recommending heartworm preventative medication for ALL dogs. We generally recommend the medication be given from the first of June, the start of the mosquito season, until two months after the first frost. Two months are critically important since the medication you give today (if your dog takes the monthly type of preventative) kills all the worms that were injected a little over a month before. In other words, the medication works in retrospect. We have recently learned that a mosquito needs to live at 70 degrees Fahrenheit for two weeks in order for the parasite in its mouth parts to develop to the point that the mosquito can infect a dog. In our climate, seventy degree weather in October and November will rarely be for two weeks straight. Therefore, we recommend giving medication two months after September or at least through December 1st.

Some clients prefer ALL YEAR therapy. The advantage to you is that the timing of the test is no longer important and can be done with your yearly routine physical examination and vaccinations. If you elect to discontinue treatment December 1st, the blood test must be performed between April and the end of May so that medication may be restarted by June 1st. ALL DOGS MUST BE BLOOD TESTED NEGATIVE PRIOR TO STARTING THE MEDICATION TO ELIMINATE THE RISK OF A SERIOUS REACTION!