Hello, my name is***** and I have over 20 years of experience as a veterinarian.I am sorry to hear that your pup has been diagnosed with heartworm, and I understand that it is difficult to come to terms with treating an apparently healthy dog with aggressive medical therapy that seem toxic.The best time to treat heartworm is before it has had time to create apparent heart and other organ damage. Rest assured that the heartworms are affecting your dog, they always will because they create altered blood flow through his heart, and inflammation in his lungs and other internal organs, it's just that at this point your dog's body is compensating for those stressors. That will change if the heartworms are present long enough. If we wait for him to get sick then permanent damage is done, and treatment becomes much more risky. Heartworm is passed from an infected dog to other dogs via a mosquito bite. The female mosquito bites the infected dog removing blood and microfilaria (baby heartworms), and then the mosquito passes those microfilaria to other dogs when it bites other dogs seeking a blood meal. It takes at least 6 months for a heartworm infection to develop and mature to the point where we can find it with laboratory testing. That's because we need adult heartworms to release antigens and stimulate antibodies in the infected dog's bloodstream and produce baby worms (microfilaria) to find it with the tests we have available. That means that your dog's body has already been compensating for his disease for at least 6 months.Ideally we would stage his heartworm disease before treatment because that will allow us to prepare for possible consequences, and determine the safest way to treat him. That means that we take radiographs of his chest to evaluate his heart and lungs, and check blood tests and urine to look for any evidence of secondary organ disease.First I recommend putting him on Doxycycline
and an ivermectin based heartworm prevention for a month or two, just as your veterinarian is started. Doxycycline kills a bacteria (Wolbachia) that lives with the heartworm and killing that bacteria first will make the worms easier to kill. It is also thought that bacteria increases the odds of having an adverse reaction to drug therapy so it is best to treat for that bacteria first. By using heartworm prevention we stop new infections and kill most of the circulating microfilaria (baby heartworms) which also improves safety when we treat the adults.The safest treatment for killing adult heartworms is a drug called Immiticide.Please do not be fooled by "holistic therapies". There are quite a few out there and their ingredients range from black walnut to garlic (which can actually be toxic for dogs). They do not work and in the meantime the heartworms continue to affect your fellow.Immiticide is in the arsenic family but it is not arsenic. The advantage Immiticide (Melarsomine) has over traditional arsenic based heartworm treatment is its slow kill rate. With traditional arsenic we had a faster kill rate which led to many more complications with clots thrown and reactions to a large quantity of dying worms at one time. With Immiticide we get a slower kill rate, which allows the body time to handle the dying worms at a more acceptable, less stressful rate, and thus decreases the amount of serious reactions we see.The safest immiticide protocol with the least likelihood of complications is a 3 dose protocol. By using 3 injections the success rate (all heartworms killed with the least chances of a reaction) will be much better then if we tried a faster kill rate. We give one injection of immiticide and then have the dog return in one month for 2 more injections 24 hours apart. In some cases with early heartworm infections we can use a two injection protocol. One injection is given every 24 hours for two days. During therapy your pup must be kept as quiet as possible. No running or heavy play
.I understand how difficult it is to keep otherwise healthy dogs quiet but the less active he is the less chances there are of throwing a clot from the dying heartworms and the reactions they create which would make his recovery even more prolonged. In most cases using a crate, walking
him on a leash and keeping things low key around your dog is enough. With some high energy dogs we need tranquilizers, but we try not to give more medication than is needed.Your best frame of mind should be that by using the appropriate treatment now and sacrificing some of his happiness now at being confined you are buying him a much better chance of an uncomplicated treatment and long term health, with as little lung scarring and heart and organ damage as possible.Your veterinarian will likely prescribe anti-inflammatory medication to help reduce the side effects we may see as the worms die and lodge in small vessels in the body. Finally if he has circulating microfilaria now in his bloodstream a month after the second immiticide injection series he should be treated for microfilaria with either ivermectin or milbemycin.Six months after therapy the adult heartworms and their microfilaria should be gone and he can be tested again for heartworm to make sure he is clear. Here is a link to the American Heartworm Society's webpage that covers testing, prevention, treatment protocols and probably will be able to answer any more of your questions and concerns: http://www.heartwormsociety.org/veterinary-resources/canine-guidelines.htmlTreating dogs with an early heartworm infection can allow them to have a normal, healthy lifespan.If you find you still have questions please feel free to reply with them.