Sarah Southard, DVM
Pets and Livestock
October is here! Cooler temperatures, beautiful fall colors, and the seemingly loved-by-everyone-everywhere pumpkin spice everything items are back. (An aside: Don’t feel obligated to provide your pets with the latest marketing gimmick pumpkin spice pet products.) As the weather cools, it’s tempting to be lax in maintaining flea, tick, and heartworm preventives. Stand strong, however! In our area, it is quite common to continue dealing with flea, tick, and mosquito problems throughout the fall and winter. These pests can cause several different serious problems for dogs and cats. I’ll focus on canine heartworm disease here.
Canine heartworm disease is a very serious, sometimes fatal disease that is widespread throughout the United States. Transmitted by infected mosquitoes, the microscopic infective larvae (an immature form of the parasite) continue their life cycle in the circulating blood of domestic dogs where they mature into adult worms up to 12 inches long. These adult heartworms take up residence in the right atrium, the first chamber of the heart. As the infection progresses, heartworms may also occupy other chambers of the heart, as well as the pulmonary arteries and the lungs.
While the infection may be treatable, treatment for heartworm disease has its own risks. Also, the damage that is done to the heart, lungs, and pulmonary arteries by the presence of the worms is permanent. Even after the worms are gone, scar tissue remains which decreases the ability of the heart and lungs to function as they should.
With mosquitoes ubiquitous in our environment, how can you protect your pets? Be certain that your pup is examined by a veterinarian at least once every year. A routine physical exam along with diagnostic testing performed at least annually is just as important for our pets as it is for us. Perhaps more so, given that they cannot communicate problems or discomforts in the same ways as humans. Testing for heartworm infection takes only a small sample of blood and about 15 minutes to perform.
The American Heartworm Society recommends that all dogs receive a heartworm preventive medication year-round and that all dogs are tested for heartworm disease every year. But if you’ve had no lapse in preventive coverage, why does the test need to be repeated?
Just as it is in human medicine, animal drugs are not always 100 percent effective. While it is very rare, it can happen that a dog continually on preventive medication might develop a heartworm infection. Also, if a dog has an undiagnosed heartworm infection and is prescribed certain of the preventive medications, it can lead to the death of the dog. It is always best to err on the side of caution, especially when the testing procedure is simple with limited risk. Talk with your veterinarian about the proper testing schedule for your dog and the preventive medication which best fits your needs.
In the unfortunate event that your dog is diagnosed with heartworm disease, discuss the available treatment options with your veterinarian. Some require a period of hospitalization and monitoring. Others can be managed on an outpatient basis. All treatment options require strict adherence to the proper medication administration schedules and strict adherence to all exercise restrictions recommended for your pet. Follow-up testing will be needed periodically to determine when an infected dog is heartworm-free and is safe to switch to a routine preventive medication and schedule.
Ensuring that your canine family members receive proper heartworm testing and prevention on a proper schedule is just one way to protect their health and longevity. Work with your veterinarian to develop a whole-health plan for your pets, giving them the best chance to stand strong for many years!
Disclaimer: This article is for general informational use only. Consult your veterinarian for questions regarding the health of your pets and livestock.