Living in northern New England, most of us assume that heartworm disease is not really a problem up here in a climate where much of the year is relatively cool or cold and several months are snowy. We tend to think of heartworm disease as being a big problem in warmer southern states. The fact is that heartworm disease can be found in all 50 states, and risk factors vary, including climate conditions, wildlife carriers such as foxes, coyotes and wolves, interstate travel of dogs and other pets, and extent of disease-carrying mosquitoes which thrive throughout the US. Furthermore, because infected mosquitoes can come inside, both outdoor and indoor pets are at risk. In sharing the information in this article, we thank the American Heartworm Society, www.heartwormsociety.org, for their educational resources.
Heartworm disease is serious and progressive. The earlier it is detected, the better are the chances for your pet’s recovery. Unfortunately, there are few, if any, early signs of the disease when a dog or cat is infected with heartworms. This emphasizes the importance of an annual heartworm test for all your furry friends. The test is done through a blood sample that can most likely be processed directly at your veterinary clinic.
Heartworm develops when a mosquito bites and takes a blood meal from an animal infected with heartworm. It takes in microscopic baby worms called microfilaria that are circulating in the bloodstream of the infected animal. Within 10 to 14 days, the microfilaria mature into the infective stage of larvae. Then, when the mosquito bites another animal – possibly your own beloved dog, cat or ferret – these larvae are deposited onto the surface of the animal’s skin and enter the new host through the mosquito’s bite wound. Once inside the new host, it takes approximately six months for the larvae to mature into adult heartworms which can live up to 7 years in dogs and up to 3 years in cats. Because of their long lifespan, the number of worms easily increases in the infected animal.
Heartworms, which are a type of parasite, mature and can grow to become a foot long. They live in the heart, lungs and nearby blood vessels of affected pets, ultimately causing lung disease, heart failure, and damage to other organs in the body. The disease can affect the animal’s health and quality of life long after treatment and the animal is parasite-free. Again, the importance of prevention is clear.
Once diagnosed as positive, treatment for heartworm depends on the severity of the symptoms and the signs which include cough and exercise intolerance. Risks and complications can arise from treatment and it can take a long period of time. Your veterinarian will decide on the best treatment protocol which will include not only medication but also limiting your pet’s physical activity. Approximately six months after treatment is completed, another heartworm test is necessary to confirm that all have been eliminated. Following that, a year-round heartworm prevention medication is advised.
The American Heartworm Society recommends “think 12” – get your pet tested every 12 months for heartworm and give your pet heartworm preventive 12 months a year. For more information about heartworm disease, talk with your veterinarian and visit www.heartwormsociety.org. Remember, a healthy pet is a happy pet and this helps to make a happy home!