Heartworms in Cats

Heartworms infect cats as well as dogs.  They often have no symptoms but over time can do significant damage to your cats heart.  As detection is nearly impossible in the early stages of the worms growth it is important to use preventative medication to avoid heartworm infections

Heartworms are transmitted from one animal to another via mosquitoes.  First the mosquito bites (sucks blood from) an infected animal thereby ingesting young heartworms and then bites a second animal (your cat for instance) during which silva from the mosquito bearing the young heartworms is secreted.  The young take about 7 months to mature and can grow up to 30 cm in your cats heart.

Some cats will not show any symptoms at all.  Others might be just little less active than others (this may appear simply to be laziness on the part of your cat).  If symptoms do develop this does not generally occur until the worms have begun reaching maturity (For example after 7 months of the worms living in them)..  The most common signs are coughing and rapid breathing which can also be indicative of some other illness. Other signs may be vomiting and weight loss which may also be indicative of other illnesses.  If untreated heartworms can kill your cat.

Blood tests that your veterinarian may perform on your cat to detect heartworms are the heartworm antibody test and the heartworm antigen test. Blood can also be tested for the presence of microfilaria or for their level of eosinophils. One thing to keep in mind is that while these tests are 99% accurate if there are adult female worms in your cat, that these tests often show no results if the worms have not matured yet or if all the worms are male.  Basically this means that a negative test does not mean your cat does not have worms, it simply means that you cat does not have any detectable adult female heartworms.  Therefore if your cat has been untreated for a long period of time it is important to have a followup visit to retest for worms.

Other test that may be performed are x-ray, angiogram or ultrasound

There are no drug approved treatment options available for cats. However, some veterinarians may use a drug designed for dogs but this option may have devastating results. The only other option available at this point is to treat the symptoms and hope for the best.   This is why preventative medications are so important.

Monthly preventative medications and annual heartworm testing. Please feel free to call us to set up and appointment.