Alopecia in cats

Some time ago, one of my cats suffered from Alopecia. The Vet at that time took blood samples, skin scrapes and various other tests, without actually tracing the reason for the hair loss. We mentioned this problem to a relative and she asked if we fed the cat fish, which we did. "try not to feed her fish" was her suggestion, and guess what--it worked!!
Obviously, fish may not be the reason for hair loss in all situations, but it could be worth a try?
Bill Payne