Treat Heartworm Disease in Cats

Until recently, it was thought that heartworm disease was very rare in cats. It turns out that, while cats are more resistant to heartworm infection than dogs, they are not immune to it. Heartworm infections are caused by the parasite, dirofilaria immitis, which is carried by mosquitos and transferred into the cat's circulation with a mosquito bite. Because cats are at risk of infection, it's important to know the symptoms and signs and to understand the treatment if you are a cat owner.

Identifying Heartworm Disease

 * 1) Look for the signs of heartworm disease. There is a full spectrum of symptoms, from no signs at all to sudden, unexpected death. Indeed, the signs of heartworm infection are quite general and can be attributed to many other causes, which makes diagnosis tricky.
 * 2) *Typical signs include: rapid breathing, coughing, lack of energy, poor appetite and weight loss.
 * 3) *Some cats also develop fluid in the belly, and experience dizziness or fainting episodes when moving around.
 * 4) *Asthma type symptoms are common, as is gagging, retching, vomiting and diarrhea.
 * 5) Take your cat to a veterinarian. If you suspect heartworms, or your cat is experiencing a combination of the general symptoms of the disease, get your cat looked at by a veterinarian. For a disease like heartworms, only a veterinarian's tests can give a specific diagnosis.
 * 6) *It's important to get your cat looked at, even if your suspicions turn out false. This will assure that if your cat is sick, it gets treatment.
 * 7) *The veterinarian confirms the diagnosis by looking for worms within the heart using a cardiac ultrasound. A skilled ultrasound operator can visualize the actual worms in the cat's heart and positively confirm the infection.
 * 8) Understand the difficulty of diagnosing heartworms. Diagnosis can present a challenge in cats, for a number of reasons. Firstly, cats are resistant hosts, meaning it is unusual to detect large numbers of heartworms circulating in the blood stream. This means a negative result when looking at a slide of cat blood under the microscope does not necessary represent a clean cat.
 * 9) *Secondly, the heartworm antigen blood test is specific to detecting female worms. If the cat has a population of adult male worms, or only one or two adult females are present, the test may show a false negative.
 * 10) *Thirdly, the blood tests looking at the body's immune response to the presence of heartworm can throw up false positives. These can occur if the cat was once infected but the worms have subsequently died. However, a positive test is an indicator of at least, previous infection, and so an antigen test for the presence of female heartworms should be run.

Stabilizing a Cat With Heartworm Disease

 * 1) Understand the limits of treatment. There is no proven treatment for heartworms and there is no drug licensed as safe in this species to kill heartworms. In addition, dead or dying worms can cause anaphylactic shock reactions or sudden death due to obstruction of vital blood vessels. Unfortunately there is a big chance that your cat will not survive, and the drug that is used to treat dogs cannot be used for cats.
 * 2) *In Japan, the current treatment is surgical extraction of the heartworms from the major blood vessels. This technique is still being refined, and remains a high risk strategy for the time being.
 * 3) Control symptoms. Controlling any symptoms of heart or lung disease with the use of diuretics and ACE inhibitors is the cat's best option. Diuretics decrease the amount of water in the body, which reduces pressure in the blood vessels and in the heart. ACE inhibitors also decrease blood pressure by relaxing the blood vessels.
 * 4) *Corticosteroids may also be used to reduce inflammation in the lungs and control allergic reactions to the worms that die naturally.
 * 5) *In the majority of cases it is a matter of sitting tight and controlling any symptoms arising due to compromised heart function.
 * 6) Treat associated diseases. For example, in addition to heartworm disease, the worms harbor a bacteria called Wolbachia. This bacteria can cause blood poisoning and organ damage. This bacteria can be killed by long courses of antibiotics from the tetracycline family.

Preventing Heartworm Disease

 * 1) Prevent heartworm disease. Prevention is by far the most desirable option. There are a variety of effective products that are licensed for this purpose in cats. They should be given or applied to your cat year round. Giving the medicine to your cat year round will assure that you are in the habit of giving it in the months when the cat is most at risk.
 * 2) *These preventatives include: selamectin (Revolution), milbemycin (Interceptor or Sentinel), and ivermectin (Heartgard and Heartgard Plus).
 * 3) Be especially diligent with prevention in warm, humid climates. A preventative should be used all year round but is essential in warm, humid weather. This is because an unprotected cat can be infected through mosquito bites, and mosquitos are most prevalent in warm, humid climates.
 * 4) Keep away from mosquito infested areas. Prevention is important when the cat lives near standing bodies of water, which encourage mosquito reproduction.
 * 5) *Eliminate standing water in your yard. The promotes mosquito breeding.
 * 6) *Don't let your cat outside when mosquitos are at their most active, in the early morning and in the early evening.

Warnings

 * Of heartworm cases in cats, approximately one third of cases occur in indoor cats. Thus, an indoor lifestyle is not necessarily sufficient protection against acquiring infection.

Sources and Citations
__PARTS__