Carole, I'm sorry to hear about Ash. This is one of my (and I'm sure many others) greatest fears. Taz's numbers are slowly moving toward the bad. But it's slow enough I don't have to do anything about it......yet.
I feed Taz wet food twice a day and have dry food available to him at all times. He has past dental issues, he had a fang removed a couple years ago.
I'm sorry I do not have any advice for you, but I'm sure there are many PTers who can help you and Ash through this tough time.