I need as much info as I can get!!! My Foster dog has a very bad case of heartworms and we are getting ready to start treatment. He is 8 to 10 yrs old and I have put enough weight on him to get him ready for treatment but have no idea what to expect. Pretty sure he has had them most of his life as I was told he has hundreds of them. We are going with the slow kill method because of his age and health. Any and all info would be greatly appreciated , ...this guy so deserves a second chance in life. thanks!!!!
HW is very serious, but it's also routine for those of us doing rescue work in the Deep South. Nearly every foster I've had since moving here has been HW+. Even the old ones. They're all still alive. (**knock on wood**) We've been very lucky.
With HW+ dogs, you don't want to let them run too much. The harder the heart pumps, the worse the HW disease gets. Low key lifestyle, and easygoing play and walks are the right approach.
Is the dog symptomatic (coughing, exercise intolerance, etc.)? Have they taken x-rays to rule out Caval Syndrome (the final, terminal stage of HW disease)? If the symptoms are bad, a little prednisone may help (it comes with side effects, but in bad cases of HW, the side effects may be worth the benefit) - your vet can help you think about whether it's needed.
In rescue in Gulf Coast region, we are seeing dogs clear HW in 6-12 months using a monthly dose of Advantage Multi and one 30-day cycle of Doxycycline (by contrast, the Heartgard/ivermectin-based preventatives were taking closer to 2 years to clear the worms). From my lay perspective, it really seems like there's something different about how Advantage Multi works on juvenile worms and weakens the adults. I can't tell you how or why, but lots of people who do dog rescue in the Deep South talk about it.
For the Doxycycline, my understanding is that they should stay on it for a full 30 days. It's usually a high dose, but it is an important part of the treatment. I've had several dogs who were symptomatic, with a distinctive cough that is from the HW, who became asymptomatic after the Doxy. It seems to really
help them feel better. Most dogs tolerate it well. There may be some tummy upset the first few days, but they seem to settle in and do just fine with it.
Our vet has us start Advantage Multi on HW+ dogs as soon as they come into foster care. We also start the Doxy right away, giving it with their AM and PM meals.
If you are thinking about doing "fast kill" treatment, most vets want them on preventative for 3 months before doing it (sometime in those 3 months, they also want the 30 days of Doxy completed). I've taken two personal dogs through "fast kill" with immiticide. I would be reluctant to start it during warm weather (my understanding is that cold weather makes the treatment easier on them and less risky). The injections are very, very painful -- some dogs suffer a lot with them. The crate rest that follows is worse. 1-2 months of crate rest is very, very tough on the dog, but very necessary after the injections. I have not lost a dog to this treatment, but I know of other rescues who have had dogs not make it through.
With a senior dog, they don't have much time left anyway, so I would be reluctant to put them through that kind of intensive restriction. I think you are right to be thinking about slow-kill options, as long as he's otherwise in good health and the disease hasn't progressed to the point that his life is in danger if the worms aren't immediately removed. Doing a full health work up might be important to make this decision (x-rays, blood work, etc.), given the age and suspected worm load.
Feel free to PM as you are going through it, if you have any questions.