That is wonderful that Lea is doing so well! If I'm understanding correctly it appears that Lea's stomatitis had two known contributing factors; her teeth and her fish allergy. It's fantastic that you were able to give her relief and without any long-term medication therapy. That is truly a success story.
HI,
I now feed raw rabbit and heart mix turkey and heart mix which is the favourite for all my cats and lamb and heart mix and sometimes Ziwipeak lamb or venison canned and dried raw which does have green lipped mussel oil in it which is seafood but that doesn't seem to affect her. I buy the raw food in blocks its cut up into serving size amounts which I defrost and it has bone etc already ground up in it.
She is coping really well and is like a different cat but it did take a while and she will probably have long term affects from not getting enough nutrition. Previously her gums were very inflamed and red and there was pus in her mouth and she was pretty miserable - having steroid shots frequently and her coat was dull she was very skinny - she did improve a lot after we took her off fish and then when her remaining teeth came out the second time I really can't fathom why the vet left that one tooth in the back as it caused her so much misery.
She doesn't ever gag now and her gums look normal minus the teeth her coat is shiny and she has gained weight - I think we have been lucky I also think the most natural diet possible is the best.