Hello Walter,
I found a little pup in a gutter 3 years ago and since becoming an adult he has been suffering something awful with his ear.He scratches at it non stop and cries out.This is not a daily thing, it comes on at anytime and then goes away- or at least subsides.I took him to the vet and she said she saw no ear mites, we flushed his ear anyway, put him on steroid tabs ( prednisone) and even antibiotics. Wjat can it be. I have given up.

Hi again, Deborah,
The most likely cause of your dog's ear problem is ear mites - it needs only a very few mites to cause a severe irritation. Another posibilty is a foreign body, such as a grass awn, but your veterinarian would have seen that, and the ear flush should have removed it.
If it is mites, antibiotics would not help, and steroids may well make it worse. I would suggest a commercial ear drops containg a miticide applied daily and massaged deep into the ear, for at least three weeks.
Happy New Year to you too,
Walter