(865) 523-6886
DOWNTOWN/AFTER HOURS URGENT CARE: 865.525.1167 | NORTHEAST: 865.523.6886 | CHOTO: 865.288.4630

DOWNTOWN: 865.525.1167

NORTHEAST: 865.523.6886

CHOTO: 865.288.4630


April marks the month for Heartworm Awareness! As many have experienced, one of the questions we ask clients is if their animal is on a heartworm preventative. Ideally, the answer would always be yes, but that is not the case. At Central Veterinary Hospital, we believe that it is essential for all pets in your household to be on a heartworm preventative. Heartworm disease is much more serious than seems. It can cause long term damage to your animal’s heart and the cost of treatment is almost always equal, if not more, than a lifetime of prevention. Heartworms are picked up from mosquitoes, which are a year-round pests. A single missed dose of medicine can result in the development of heartworms in your beloved pet. We want clients to be well educated about the disease and to learn about some of the misconceptions that we often encounter at Central Vet. Because heartworms are such a big problem and our doctors see so much of it, we asked them to share some of the things they really wish people knew about this disease. Here’s what we learned from what they have to say. 


Heartworm disease is still occurring in this day and age. While we have come a long way from the first discovery of canine heartworms in 1856, they are still a prominent problem today. Despite easy access to numerous methods of prevention, we still see heartworm positive animals. Why is that? While it is less likely to occur in drier parts of the country such as Montana and Wyoming, it is still present. Heartworms can be transmitted at any time during the year when a dog is bitten by a single infected mosquito. It does not depend on the weather nor the season, because a single missed dose can result in the heartworms developing further in the animal. Even in the south when it reaches cold temperatures, mosquitoes can stay alive in humid and moist environments, such as sewers and storm drains. We do not want to see your animal become a victim of this disease, so it is important to recognize that the risk exists year round. Give your pet their monthly dose of heartworm prevention and make sure they eat it, or come in for their 6- or 12-month ProHeart injection before it is too late. This disease is preventable and it is worth the cost of getting the prevention.


To many, heartworm disease may seem like a seasonal occurrence similar to the flu in humans. However, as long as there are mosquitoes around, it will always be present. Our animals can get the disease from the single bite from an infected mosquito. Just one bite is all that it takes. In the grand scheme of things, it is much easier to prevent the heartworm larvae from developing by giving a monthly medication than it is to constantly monitor for the presence of mosquitoes near these animals. It does not matter whether they are strictly indoor or not, as long as there is an opening to the outdoors for mosquitoes to fly in, they are at risk. If you open any door to go in and out of the house, they are at risk. If you open your windows when it is nice out, a single torn wire in a screen can allow a mosquito access to the inside of your house. Your pets are at risk if they go outside and play all day, but so are the ones who stay inside and lie around.  

Price Comparison between Prevention and Treatment: 

The cost of heartworms is much more than just the effect on your animal’s health. The price of treatment for a dog that has heartworms is much more expensive than preventing it. According to the American Heartworm Society, the typical cost of treatment for a 40-lb dog can cost between $1,200-$1,800. Year round prevention, on the other hand, costs between $70-$200. It is much more cost effective for you and your animal to stay on year round of prevention rather than risking it to save a few dollars. Treatment itself does not prevent your dog from heartworms after it is completed.

Long Term Health Consequences:

It is important to know that heartworms aren’t a disease that your pet gets once and then gets over. Even if the heartworms are discovered early and treated appropriately and immediately, they cause permanent damage to your pet. Heartworm treatment, when done as recommended, still takes several months to complete and there is damage occurring within the cardiovascular system that entire time. If the heartworms are not discovered early, or treatment is not immediate and ideal, that damage becomes worse and worse over time and eventually becomes permanent. Heartworms cause permanent damage to the heart and lungs that can kill your dog many years after they are once again negative for heartworms, and this is why annual testing and immediate treatment are so important. Sadly, one of the most common reasons for this permanent damage is when pets are treated with “slow kill” methods. This basically consists of continuing to give monthly heartworm prevention until the heartworms die. Since the natural lifespan of heartworms is five to seven years,  this allows lots and lots of time for damage to accumulate in the dog’s body. he risk of sudden death exists as long as heartworms are present in the body, so it’s actually much more dangerous both in the short and long term to attempt slow kill than to treat with the recommended series of injections.


Heartworm disease takes a bigger toll than what we perceive. With the presence of mosquitoes at all times of the year, it is important to have year-round protection. The mosquito is the main player in the game and we cannot control which ones do and do not have the infective heartworms nor can we truly control whether they get to our pets or not. The long-term effects of heartworm disease are detrimental to an animal’s health, even after recovery. Even the cost of treating heartworms outweighs the cost of getting prevention. With heartworms being so easy to prevent and so dangerous to your pet, why would you not?


Stanford. “History of Discovery.” Standford.edu, 2006, web.stanford.edu/group/parasites/ParaSites2006/Dirofilariasis/History.htm.