How does my pet get it?
Heartworm is transmitted by mosquito bite. When a mosquito bites an infected dog it ingests the young worms from the bloodstream. In 10-45 days, the worms inside the mosquito reach the infective stage of their maturity and the mosquito can infect another dog with its bite. It takes up to 6 months for the worms to move to the heart and become sexually mature adult heartworms.

What are the signs?
There are no outward signs of heartworm infection in the early stages. At the advanced stage of the disease, you will see coughing, weakness, weight loss, exercise intolerance, and poor hair coat.

How is it diagnosed?
Heartworm disease can be diagnosed by a simple blood test. The heartworm test detects antigens produced by female adult heartworms. Since it takes 6 months for a heartworm to reach adult maturity it is possible to get a false-negative test result. If the test is positive, further procedures such as blood profiles, ECG, and radiographs are done to determine the extent of the disease and whether your dog can tolerate the treatment.

Is there a treatment?
Yes, the treatment involves several injections of an arsenic drug which destroy the adult worms. Since arsenic is a toxic drug, it is very important that your dog's liver and kidney functions are normal. Strict confinement is essential for 4 weeks following the treatment because the dead worms will break up and be absorbed by the body. Complete cage rest will prevent a major pulmonary embolism. Further treatment involves the elimination of immature worms in the bloodstream and 4 more weeks of restricted activity. About 4-6 months after treatment, another blood test is done to determine a heartworm-negative status.

How can it be prevented?
Because of the risk and cost involved in treatment, heartworm disease is a lot safer and cheaper to prevent. Heartworm preventative comes in a daily or monthly chewable tablet form and the dosage is based on your dog's weight. For effective heartworm prevention you must adhere to the drug instructions. If you are using the daily preventative, your dog must not miss a single dose. If you are using the monthly preventative, you can improve the absorption rate by breaking it into smaller pieces before giving it to your dog. Always make sure your dog does not spit it out or vomit after giving it. Because mosquitoes are around all year in this area, we recommend year- round heartworm prevention.

How often should my dog have a heartworm test?
Puppies under 6 months old do not have to be tested before they start the preventative, but should be tested when they are 1 year old. If your dog has an unknown history or has never been on heartworm preventative, a heartworm test is required before starting the prevention and should be tested again in least 6 months to insure a negative heartworm status. We strongly recommend that dogs on year-round heartworm preventative be tested at least every other year. If you suspect that your dog missed one or more doses, you should have a heartworm test performed 6 months from the time the first dose was missed.

For more information about heartworm disease, the American Heartworm Society has a website at www.heartwormsociety.org