Heartworm treatment for horses used on dogs? - Page 1

I have a Great Pyreneese that has not been with me very long. She has had two surgeries in the last seven months and we are all okay on that front but in getting her totally up to date on everything I just learned she is positive for heart worms. A friend of mine, knowing how stressed out I am about the financial issues with her surgeries and prescription dog food, suggested using the same treatment they use on horses. I am nervous about this as I don't have any experience and my vet has been less than helpful in explaining the reason it would not be good other than to say it is for horse and it would likely kill her. Anybody have experience or suggestions with this?