What is Heartworm Disease and How to Help my Pets!

What is heartworm disease?

Heartworm disease is a serious and potentially fatal disease in pets in the United States and many other parts of the world. It is caused by foot-long worms called heartworms that live in the heart, lungs and associated blood vessels of affected pets, causing severe lung disease, heart failure and damage to other organs in the body. These worms can cause damage to dogs or cats as they mature into fully matured parasites.

In dogs, they are a natural host for heartworms, which means that heartworms that live inside the dog mature into adults, mate and produce offspring. If untreated, their numbers can increase, and dogs have been known to harbor several hundred worms in their bodies. These worms then cause them to have symptoms that their owners will notice.

In cats, the heartworm disease is very different from heartworm disease in dogs. The cat is an atypical host for heartworms, and most worms in cats do not survive to the adult stage. Cats with adult heartworms typically have just one to three worms, and many cats affected by heartworms have no adult worms.

How is heartworm disease transmitted from one pet to another?

The mosquito plays an essential role in the heartworm life cycle. Adult female heartworms living in an infected dog produce microscopic baby worms called microfilaria that circulate in the bloodstream. When a mosquito bites and takes a blood meal from an infected animal, it picks up these baby worms, which develop and mature into “infective stage” larvae over a period of 10 to 14 days.

What are the signs of heartworm disease in dogs?

In the early stages of the disease, many dogs show few symptoms or no symptoms at all. The longer the infection persists, the more likely symptoms will develop. Active dogs, dogs heavily infected with heartworms, or those with other health problems often show pronounced clinical signs.

What are the signs of heartworm disease in cats?

Signs of heartworm disease in cats can be very subtle or very dramatic. Symptoms may include coughing, asthma-like attacks, periodic vomiting, lack of appetite, or weight loss.

All dogs and cats should be tested annually for heartworm infection, and this can usually be done during a routine visit for preventive care.

Following are guidelines on testing and timing:

Puppies under 7 months of age can be started on heartworm prevention without a heartworm test (it takes at least 6 months for a dog to test positive after it has been infected), but should be tested 6 months after your initial visit, tested again 6 months later and yearly after that to ensure they are heartworm-free.

Adult dogs over 7 months of age and previously not on a preventive need to be tested prior to starting heart worm prevention. They, too, need to be tested 6 months and 12 months later and annually after that.

You need to consult your veterinarian, and immediately re-start your dog on monthly preventive—then retest your dog 6 months later. The reason for re-testing is that heartworms must be approximately 7 months old before the infection can be diagnosed.

What happens if my dog tests positive for heartworms?

No one wants to hear that their dog or cat has heartworm, but the good news is that most infected dogs and cats can be successfully treated. The goal is to first stabilize your pet if he is showing signs of disease, then kill all adult and immature worms while keeping the side effects of treatment to a minimum.

After all, our pets are our family and we want them to be healthy and happy. Give Fox Creek Animal Hospital a call for all our preventative and treatment options available for dogs and cats.