her teeth are healthy and she has a clean bill of health from her vet. Her temperament is moody and shy, but she can also be very aggressive to the dogs, which have lived with us for 3 and 7 years respectively. I have changed food brands several times, but has had no effect on her behaviour.

My cat does exactly the same thing!! We took her to the vets and he said it's completely normal and particularly common in shy or aggressive cats(my cat is also very shy). He said there's no need to worry unless she is losing a lot of weight. So if your cat is losing a lot of weight then take her to the vet and they will sort that out but otherwise it's perfectly normal and you just have a lot of cleaning up to do, as do we! lol Try to stick to the same brand of food as well, as we did what you did and changed them to see if this helped but the vet said to stick to one that she likes the taste of and now she has started to get used to it and isn't sick as often as she used to be. :) pets question and answers,www.5d2d.com
Hope this helps!

same experience

To answer your question, take a few pieces of kibble and put them in a glass of warm water, and watch what happens after a few minutes. The pieces swell to many times their size. Cats don't chew (look at her teeth, they are designed to rip meat off bones, not for chewing) so the pieces are swallowed whole or nearly whole, swell in the stomach, and then back up they come. Dry food diets aren't the healthiest for your cat - an all-dry diet is now linked to such feline disorders as obesity, diabetes, constipation, urinary tract disorders and kidney disease. Nature created cats to eat meat, not dry corn-filled kibbles. Many cats also are intolerant (or become intolerant) of corn, and it can cause gastro intestinal upset, also leading to vomiting. Feeding her a better quality food (you'll need to go to the pet store and actually read the ingredients on the bag) free of corn may help, and adding canned to her diet will definitely help.

many years of cat rescue

My 10 year old female calico does this too, but she only does it if the food in the bowl gets just a tiny bit low. My cats "self feed" so when the feeder doesn't automatically drop the fresh food to the bowl she freaks out, gorges herself then throws it back up...

Are you sure your cat's teeth are healthy? If so, he might have something stuck in his throat! Go and consult the vet ASAP! My cat acted the same. Bit don't worry, the chances of him being fine are 110%! Good luck to you and your cat!