I just bought n=my dog from a animal shelter. a couple dyas later brought her to the vet. to get a check up and found out she has heart worm. the vet told me it will cost $450 to get her well. they also told me it might not work.
I recommend that you go back to the shelter. Maybe they can help you with the $$. Immiticide is commonly used to treat heartworm infection and the recovery rate is good. vetcare