Heart Worm Prevention for Pets

Heart Worm Prevention for Pets

With warmer temperatures approaching, mosquitoes will soon be making their comeback.  And with that comes a variety of mosquito-borne illnesses, for both people and their four-legged companions.  One common disease that is prevalent in our area is heart worm disease.

Heart worm is caused by foot-long worms that live in the heart, lungs and blood vessels of affected pets.  This can cause lung disease, heart failure and damage to other organs.  While it is most common in dogs, heart worm disease can also be found in cats, ferrets and, on the rare occasion, humans.

Wait!  Cats can get heart worm?  Yes.  They can.  Although it is not as common in cats as it is in dogs, your feline friend can also contract heart worms.  However, cats are atypical hosts for heart worms and most worms don't survive to the adult stage.  However, for the felines that have adult heart worms, they usually only have between one to three worms.

So, how is heart worm disease transmitted from one pet to another?  We'll give you one guess.  If you thought mosquitoes, you guessed correctly.  The mosquito plays an essential role in the heart worm life cycle.  Adult female heart worms living in an infected animal produce microscopic baby worms called microfilaria that circulate in the bloodstream.  When a mosquito bites an infected animal, it picks up those baby worms, which develop in to "infective stage" larvae within 10 to 14 days.  Then, the next time that mosquito bites another animal, the infective larvae end up on the animal's skin and enter the new host through the bite wound.

My pet was bitten recently.  What signs should I look out for?  If you have a dog, signs of heart worm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss.  As the disease progresses, the dog may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen.  Dogs with a large number of heart worms can also develop a life threatening form of cardiovascular collapse called caval syndrome.

Similar to dogs, signs of heart worm disease in cats include coughing, lack of appetite and weight loss. Other signs include asthma-like attacks and periodic vomiting.  Occasionally, a cat may have difficulty walking, experience fainting or seizures, or develop fluid accumulation in the abdomen.  Sadly, the first sign in some cases of heart worm disease in cats is sudden collapse of the cat, or sudden death.

I keep my pets inside.  Do I need to have them on heart worm preventatives?  Infected mosquitoes can come inside your home. Therefore, both indoor and outdoor pets are at risk.  To protect your pets, the American Heart worm Society recommends that you "think 12."  Make sure to get your pet tested every 12 months for heart worm.  Give your pet heart worm preventative 12 months a year.

When should I get my pet tested for heart worm?  All dogs should be tested annually.  Heart worm infection in cats is slightly harder to detect than in dogs.  Your veterinarian may use x-rays or ultrasound to look for heart worm infection.  The preferred method of screening for heart worm in cats is using both an antigen and an antibody test.   Talk to your vet about heart worm prevention and what needs to be done to keep your four-legged companion heart worm free.

My pet tested positive for heart worm.  Now what?  If you are a dog owner, you should confirm the diagnosis first using a different test.  Because heart worm treatment is both expensive and complex, you and your veterinarian will want to be absolutely sure that treatment is necessary for your animal.  If that second test also comes back positive, you'll need to restrict exercise almost immediately.  Any type of physical exertion will increase the rate at which the heart worms cause damage to your pet's heart and lungs.  Before treatment can begin, your dog's disease may need to be stabilized.  Once your veterinarian has deemed your dog stable enough for treatment, he or she will recommend a treatment protocol involving several steps.  And, finally, you must test and prevent for success.  Six months after your dog's heart worm treatment ends, your veterinarian will perform another heart worm test to confirm that all heart worms are gone.

If your cat tests positive for heart worms, your vet will diagnose the severity of the case.  But, diagnosis can be complicated and may require a physical exam, an X-ray, a blood count, blood tests and, possibly, an ultrasound.  Unfortunately for cats, there is no approved drug therapy for heart worm infection in cats.  Despite that fact, cats with heart worm disease can often be helped with good veterinary care.  Your veterinary may recommend hospitalization in order to provide therapy, including intravenous fluids, drugs to treat lung and heart symptoms, antibiotics, and general nursing care.  And, just like with dogs, you'll want to maintain prevention to keep new infections from developing.