Recently at Snake River Veterinary Center, I diagnosed a case of Heartworm Disease. Since I have been in practice, a little over four years now, I have only diagnosed one other case at our clinic. Diagnosing this disease is a daily occurrence for veterinarians in the south, but not something we see every day in our area. Fortunately for us and our sweet patient, the owners have elected to pursue treatment.
Heartworms are spread from mosquitoes and virtually 100% of unprotected dogs could contract them in high risk regions. The disease does occur in cats as well, but it is not as common. Although the disease is common along the Ohio/Mississippi river basins and Atlantic/Gulf coasts, it is has been diagnosed in all 50 states. The carrier of the disease is the mosquito and the life cycle is as such: As an infected mosquito takes a blood meal, the heart worm larvae are passed into a dog’s bloodstream. The larvae then travel to the heart where they molt into several other larval stages before developing into an adult. The process from infection, to development of adult worms, takes 6 months. Once an adult worm is present in the heart, they can then reproduce and new larvae called Microfilaria, circulate in the bloodstream. At this point, when a non-infected mosquito takes a blood meal from an infected dog, they are infected with the Microfilaria. The Microfilaria molt into different stages within the mosquito, and are then ready to be a source of new infection when the mosquito takes another blood meal.
All dogs and even cats should be tested for Heartworms annually. The test is simple as we only need a drop of blood from your pet, and it only takes 10 minutes to process. Heartworms can be prevented with use of a monthly Heartworm preventative such as Sentinel, Heartgard, Iverhart, etc. The treatment for adult worms however, is more challenging, expensive, and lengthy.
As mentioned earlier, we recently diagnosed a case and have been given the privilege to treat her. She is a native of the south and is a rescue dog. We were performing our Wellness Special at the clinic which included a Heartworm screening test, when we diagnosed her. She showed no outward signs of the disease, as it was diagnosed very early. Some dogs that go undiagnosed develop heart failure and are more difficult to treat.
Treatment for her Heartworms began today. We would love to include all of you in the process as we move forward with her treatment. The American Heartworm Society recommended treatment protocol will take 120 days to complete.
Today we administered a heartworm preventative called Sentinel. We pre-treated with an injection of benadryl and a steroid. We are observing her and enjoying her company throughout the day, to monitor for any signs of reaction. She will also go on an antibiotic called Doxycycline today and it will be given twice daily for 1 month. Heartworms can carry bacteria, so we must kill the bacteria first to try to minimize reactions. We also are killing the Microfilaria at this point with administration of the preventative Sentinel. The overall goal of this process is to kill the “babies” (Microfilaria), eliminate the bacteria, and then slowly kill the adult worms. If the adult worms are killed to soon or suddenly, they may cause a stroke or an anaphylactic reaction/shock.
In 30 days, she will receive another preventative (Sentinel). In 60 days, we will administer a preventative, along with starting the adulticide injections to kill the adult Heartworms. She will be on steroids to prevent reactions and her activity level will have to be very restricted. At day 90 and 91 she will get another set of injections to kill the adults, and she will be tested at 120 days to see if our treatment was a success.
It is going to be a long and challenging road ahead for this sweet girl and her family. Please follow us as we move through this process and give support to “Bailey” and her family. We will post updates as she moves through her treatment protocol.
To conclude this blog, I hope I was able to bring some general awareness to Heartworm Disease and Prevention. Monthly preventives are highly recommended along with annual heartworm tests. If you have any questions, please feel free to call (208) 452-7950.
Jenny Janitell, DVM