By: Elizabeth Alexander, DVM
Ambassador Animal Hospital
What are Heartworms?
Heartworms are a type of parasitic worm that lives in the heart and pulmonary arteries of its host. As an adult, the worm can be up to 14 inches long! It attaches to the heart or vessel wall and feeds on blood. An adult Heartworm can wriggle around inside for up to 7 years!
That sounds horrible, what kind of damage does the worm cause?
The heartworms cause inflammation in the lungs and airways. They can cause pooling of blood and blood clots. Over time the worms cause the heart walls, and arteries in the lungs to scar, which causes trouble with heart function. Not to mention the bodies of the worms themselves cause blockages in the arteries, blood flow issues, and eventually lead to heart failure.
Are you saying the Heartworms can kill?!
Yes, the more heartworms that are present in the heart, the faster they can kill. But even a small number of Heartworms cause damage to the heart and lungs and shorten life spans. Large amounts of worms lead to heart failure and death faster.
Who can get Heartworms?
Heartworms can infect dogs, cats, ferrets, and some wild animals such as wolves, coyotes, and foxes. The dog is considered the natural host, or preferred host, but wild animals are considered important carriers of the disease.
How can my dog get Heartworms?
The larval stage of heartworms is carried by the mosquito. When the mosquito bites your dog, the larva drops out of the mouth of the mosquito and into the bite wound. After being infected, it takes about 6 months for the larval heartworm to mature into an adult worm in your pet’s heart.
Is there a test for Heartworms?
Yes! There is a simple blood test to check for heartworms. It takes just three drops of blood and can be conducted by your veterinary healthcare team. The American Heartworm Society recommends annual testing for every dog. Heartworm infection is a treatable condition if diagnosed early. If your dog tests negative, you can have the peace of mind that your dog is heartworm-free.
What about Heartworms in my cat?
Cats can get heartworms, but they are not the natural host, so the worms have a harder time surviving into adulthood. However, IF even just one heartworm were to mature in a cat’s heart, the results can be devastating. Symptoms can be very mild at first and go unnoticed, like a mild cough, or occasional vomiting, or weight loss. Sadly, often the first sign that is noticed is collapse or death. The treatment that is possible in dogs, does not work in cats. So, prevention is the only way to protect these fur babies. There is however a test for heartworms in cats, just like there is in dogs. If you are concerned about your cat being exposed to heartworms, talk about testing with your Veterinary team.
You mentioned Prevention, can I prevent Heartworms in my pets?
Yes, there are many options for preventing heartworms in our dogs and cats. We typically think about heartworm prevention for dogs. Dogs can take prevention orally, topically, or by injection. We recommend orally, or by injection. There are many brands of oral heartworm prevention. You may have heard of Heartgard, Simparica Trio, or Sentinel. The injectable prevention is called ProHeart. The price of these preventions varies, but many types are quite affordable. Certainly, prevention is MUCH less expensive than treatment! Cats are typically treated topically with heartworm prevention, this is because cats can be VERY difficult to give a pill! Brands such as Revolution Plus, or Bravecto Plus provide heartworm prevention as well as coverage from fleas and ticks.
Should I really give my pets Heartworm Prevention?
Yes! The risk-cost analysis would break down something like this: Preventions come in a variety of forms that are easy to administer and well tolerated and cost roughly $10 per month. Treatment costs ten times that much, and the heartworms cause permanent scarring and damage to my pet’s heart and lungs, even when treatment is successful. If I have a cat, she might die before I find out she has heartworms. It’s definitely worth preventing!
What about in the colder months? Or what if my cat is indoors only?
Mosquitos, the carrier of the infective stage of heartworms, are mainly active in South Carolina from March until October. However, as you may have noticed, our weather can be quite unpredictable, making it hard to say when mosquitoes will really emerge or be active. Also, mosquitoes do not die in the winter but hibernate in temperatures under 50 degrees. This means that if we get a warm snap in November or December, mosquitoes could re-emerge and be a problem. For these reasons, The American Heartworm Society recommends heartworm prevention 12 months a year. It’s better to be safe than sorry, or glued to the weather channel! As for our indoor cats, mosquitoes get inside. The risk of infection is less than for an outdoor cat, but it’s still present. Be aware of your own home, and if you are ever seeing mosquitoes inside your home, then your cat needs prevention.
So basically, you are saying that Heartworms are very harmful, and even deadly, to my dogs and my cats. But I can easily prevent them by giving once monthly preventions. Or having my veterinarian give an injection to my dog. Also, I should have my pets tested once a year for heartworms, just to make sure everything is ok.
Yes! An ounce of prevention is worth a pound of cure, and we want to ensure that our pets live long and healthy, parasite-free lives!
For more information visit: www.heartwormsociety.org