Heartworm Disease: Healthy Pet/Happy Pet 3

Article Series for Dunes Living Magazine

From: Dr. Amanda Thomas

As springtime approaches and the weather along the Grand Strand warms up to more enjoyable temperatures, we will all be out and about, walking, running, biking, hiking and exercising with our dogs; enjoying the beach, the dog parks and feeling the sunshine we missed so much over the winter months! What a nice time of year to be outside, remembering why we decided to live in the wonderful climate of Myrtle Beach, South Carolina.

What else loves the warmer temperatures? Parasites; bugs and critters, insects and crawly things, some that fly and some that occupy space in our lawns and landscape. Many of these insects carry diseases that infect our pets (dogs and cats) when they find them, bite, sting or attach to their skin to take a meal. Yuck, right?

Heartworms (Dirofilariaimmitis) are parasitic roundworms that cause a deadly disease in dogs and cats and are transmitted by mosquitoes. South Carolina is one of the most endemic states in the country for this disease, which means our mosquitoes are carriers and all of our dogs and cats are at risk for contracting heartworm disease, whether our pets live inside, outside, or a combination of both. When a mosquito bites an infected animal and takes a blood meal for itself, it ingests the larval stages of the worm (the eggs or microfilaria). When that mosquito floats into the next yard or into your home and bites your dog or cat, it injects those larvae into the bloodstream of your animal. Over the course of about 5-6 months (the pre-patent period) the larval stages of those heartworms will grow and develop into very large adult worms which live in the vessels of the heart and lungs and cause severe, life-threatening disease. If undiagnosed and untreated the animal will die as a result of congestive heart failure.

Dogs are the intentional hosts for heartworms, as well as other mammals like coyotes, foxes, wolves, ferrets, and the occasional human. Cats are atypical hosts but are still very susceptible to the disease.  Signs are not present in our pets until adult worms are present in the heart and lungs, causing a cough, exercise intolerance, respiratory problems, circulatory issues, and weight loss. Sounds terrible right? Well, it is.

The good news is that Heartworm disease is entirely preventable.

But before preventive measures can be instituted in dogs, they need to be tested for heartworm disease with an antigen blood test that takes about 10 minutes in the veterinary hospital and tells us whether an animal has even 1 female adult heartworm in their body. If the test is positive for the disease, the veterinarian will then look at the blood sample under the microscope to determine if there are microfilaria (larvae) present in the peripheral blood sample. If so, the patient is diagnosed as being positive for the disease, and further testing is necessary before a treatment plan can be implemented. In some cases, when the disease is so far advanced, it may be decided that the risk of treatment does not outweigh the benefit to the animal and no cure is available. If treatment is an option, it is very expensive and not without risk to your pet.

In cats, the testing for Heartworm disease is not routine because the disease manifests itself differently. The typical infection in a cat is primarily in the lungs, not the heart, and most cats do not have circulating microfilaria, making it much harder to diagnose. 75% of cats with heartworm disease will show signs of chronic respiratory disease, coughing, wheezing, vomiting, and weight loss. One of the myths of Heartworm disease in cats is that indoor cats are not susceptible – yet, over 25% of cats that test positive for Heartworm disease are cats that live INDOORS only. Mosquitoes can get inside our homes and can cause this disease in our indoor cats. A monthly preventative product should be used in cats whether testing for the disease has been done or not – a very different recommendation than in dogs.

So how do we prevent this deadly disease in our dogs and cats?

Every month, year-round, for your pet’s entire life, you should provide them with heartworm preventive medication.

There are many of these products on the market these days, and your veterinary team can give you the best advice on which to use based on your family of pets.

I recommend a monthly chewable treat for dogs, like HeartGard Plus – this product protects your dog 100% against the disease when given monthly. The dogs love it since it is a beef-flavored treat, and it is also an excellent monthly gastrointestinal dewormer.

For cats, I usually recommend monthly administration of a topical liquid that is applied to the skin at the base of the neck called Revolution. Not only does this provide protection against heartworm disease but it is a dewormer, a flea and tick preventative, protects against ear mites, and kills other external parasites as well.

For less than the cost of 2 lattes, you can purchase one of these lifesaving products for your pet each month. I’d say that’s a pretty good deal!

Because our weather conditions rarely allow for a complete kill of parasite eggs and larvae over the winter months, parasitic diseases are at the forefront of what veterinarians treat in southern states. Talk to your veterinarian about recommendations for your pets.

The veterinary team is there to help you, offer advice and provide support when you need it.

When it comes to Heartworm prevention, take their advice and keep your pets free of this preventable disease.