Originally Posted by Nolia
If he rushes between 1 - 5 minutes. The food is undigested, often not even chewed through.
That sounds exactly like what used to happen to my Stumpy. It's not the fact that the food is not chewed through. Stumpy is now toothless and he "sucks" dry kibble in without chewing it at all, yet does not throw it up now.
I originally thought that his issue was related to chowing down too much food too fast. As alpha cat in my house, he was always first to the food bowl and would keep others out while he had his fill. Within minutes of him eating, he would vomit it back up. Then we changed food one day and the vomiting stopped.
Just hearing your issue, it sounds like he either has an allergy issue with the foods you are giving him, or he has something physically wrong with him. If raising the food bowl up isn't helping him, there is clearly something else going on with him.
An allergy is a broad term. I claim to be allergic to eggs, but my issue is really that I can't digest them so they come back up. Lactose intolerant people have similar issues with dairy products. I think it's time to challenge your vet a little bit more about what is going on.