Does my dog need heartworm protection?

in Pets by

By Dr. Parker T. Barker

The short answer is “yes” they do. Heartworms are caused by a long, thin, nasty worm that lives in the blood vessels and heart of infected dogs. The disease is spread from dog to dog (and to cat) by mosquitoes. It is a serious parasitic disease. The mosquito bites a dog with a heart worm infection, collects some of the microscopic heart worm offspring and then, after a couple of weeks, passes these on to another dog or cat.

Inside your dog, if left untreated, these worms can grow to more than 12 inches. And, simply stated, it can kill your dog. But it is also very easy to prevent.

Heart worms are found in most parts of the United States. Mosquitoes are the key – without them the disease cannot spread. The highest rates of infections are found in subtropical climates like those of the southeastern United States, the Gulf States and Hawaii. However, heart worms are also found throughout the central and eastern United States, particularly near oceans, lakes, wetlands and rivers. Sounds a bit like the Lowcountry to me….

How do I know if my dog has heart worms?

If your dog isn’t on a monthly regimen of heart worm preventative medicine, pay attention if your pet seems unusually tired, coughs a lot, or loses a bunch of weight suddenly. Heart worm infection in dogs is usually diagnosed by a blood test. Talk to your Vet immediately if you have concerns about heart worms in your pet. Early detection makes the difference between life and death and I really mean that.

How do I prevent heart worm disease?

Prevention of heart worm disease is simple. In most cases, a once-monthly prescription tablet or topical treatment is all that is needed to effectively protect your pet. These products include milbemycin oxime (Interceptor Flavor Tabs® and Sentinel Flavor Tabs®), ivermectin (Heartgard® for Dogs), and topical selamectin (Revolution®). These preventatives are only available from your veterinarian who must first make certain that your dog is not heart worm positive before you start the treatment.

You should have your dog tested for heart worm every year when you get them their annual Vet check-up. Repeated heart worm blood testing every year is recommended even for dogs taking heart worm preventative year round. Testing is also recommended when a pet owner switches between preventative medications. Annual testing will ensure that an infection is caught in plenty of time to effectively manage it if Fido has managed to get heart worms.

Some heart worm preventatives also control other intestinal or external parasites that afflict dogs.–kind of multiple protection from yucky stuff. And, from personal experience, the pills don’t taste too bad.

There is an American Heart Worm Society ( where you can read about all things heart worm related. There you will also find the AHWS guidelines for how you should prevent your dog from getting these nasty, icky worms in the first place. But the easiest place to get good information is to chat with your Vet.