How to Test Cats for Heartworms Before Giving Heartworm Pills

The incidence of heartworm in cats is on the rise and it is virtually impossible to treat a cat once it is infected. Concerned cat owners may worry about whether their cats are at risk, whether they should be given preventive medication, and whether testing should take place before doing this. While the title of this article may imply that cats can be tested for heartworm at home, please note that the actual testing requires a blood sample and should only be done by a veterinarian. It is, however, the owner's responsibility to decide if testing is needed and if so, how and when it should take place. Read on for information that will help you assess your cat's risk for feline heartworm disease and weigh the pros and cons of testing and preventive treatment.

Instructions

1

Consider your cat's risk level for FHD (feline heartworm disease) in light of three key factors. First, your geographic location. The southeastern part of the U.S. is prime heartworm territory; the parasites are transmitted via mosquito bites, and the longer the period of time that mosquitoes are viable, the higher the risk to cats. Overall, there's considered to be a 7 to 10% risk of a cat developing heartworm in the U.S., but in Florida and Lousiana, the actual risk may be over 20% while it may drop to under 7% as you move further north and west.

2

Understand that the second risk factor your cat's overall health and immune system strength may be more important than your location. This has to be considered because heartworm does not affect cats in the same way it affects dogs. With dogs, the key concern is the possible obstruction of blood flow because of the size and growth of the worms. However, the cat is not a natural host for heartworm, and will typically mount a massive immune response when infected with it. The inflammatory reaction that results from a single worm can actually cause sudden death in older or relatively frail cats, and this can happen without any apparent symptoms.

3

Re-evaluate your cat's outdoor/indoor status if he/she cat spends any time outdoors. Obviously, outdoor time will increase the odds of exposure and in turn, your need to test and vaccinate. However, this doesn't mean that indoor cats are safe; mosquitoes get into houses and bite people so they can certainly manage to bite cats as well! Furthermore, indoor cats may be more vulnerable once infected as they are likely to mount a stronger immune response.

4

Discuss testing and preventive treatment with your vet if you conclude your cat may be at risk for FHD after considering the issues in steps 1 through 3.Your vet will be aware of the prevalence of heartworm in dogs from your area; if infections are relatively rare, you may not need to take any further action. But since there is no effective treatment for FHD once it develops, many vets are coming to believe it may be wiser to undertake preventive treatment than to take any chances. It is important to test before beginning treatment, and in high-risk areas, to do so before undertaking procedures such as spay/neuter or dental treatment. If a cat is harboring FHD and shows no symptoms, such benign procedures can cause unexpected complications.

5

Ask the vet about the type of test to be used. According to guidelines established by the American Heartworm Society, both an antigen test and an antibody test should be used. These can generally be done at the same time, from the same blood sample. If your cat is having blood drawn for some other reason, you may want to avoid a separate visit and blood draw by asking if the FHD tests can be done at the same time. If one or both tests indicate a possible infection, you will need to follow up with other diagnostics such as a thoracic x-ray or echocardiogram and discuss treatment options. Hopefully, your test results will be negative and you can begin preventive treatment.

6

Be sure your vet is up to date on the latest preventive methods available. Currently, there are two oral and two topical medications that can be used for cats. You can find more information on these in the Resources section. Topical medication may be preferable as it will reduce the need for annual retesting. One of the reasons dogs need to be retested each year is to make sure the previous year's treatment was effective. Both dogs and cats can conveniently vomit up pills or chewable medications you give them, and may do so without your knowledge.