Has anyone treated heart worms?

I used the ivermectin treatment to rid heartworns in two 3 year old dogs that lived on a marsh and never had heartworm preventive. One was a cur, the other a dogp/American Bulldog cross. When they were given to me they could not run across the yard and coughed all the time.

It took a year, and at treatment time they had hyper sensitivity to their paw pads, acted like they were walking on sharp gravel when actually on smooth concrete. May have been a symptom of ivermectin overdose toxicity. A veterinarian friend of mine said they may lose part of a lung, if they survive at all. they lived and both can run with the best of them today. the bulldog/dogo still has a mild cough that she loses right away and can catch and hold a bad hog and run a half mile and catch another. The cur is a go-yonder type and routinely makes 1-2 mile casts and has run hogs up to 7 miles before they bay up. So I think the lung damages were minimal. the treament cost me $35 for the bottle of swine/cattle ivomec.