By Alfred J. Plechner, D.V.M.
Cats vomit for a number of reasons. The most common reason why cats vomit is due to ingesting hair while cleaning themselves.
The 2nd most common reason why cats vomit is due to a hormonal antibody imbalance. In 70 % of the vomiting cats, there will be a red line at the edge of the gum, where it joins the enamel of the tooth. I refer to this as a gingival flare.
The 3rd most common cause of vomiting in cats, comes from eating plant material, and other foreign bodies, to help move ingested hair through their digestive tract. Also an enzyme deficiency from the pancreas can create this need to eat plant and foreign materials.
Believe it or not, the leased common cause of vomiting in cats comes from food allergies. Before you try changing foods, 1st try a hairball deterrent, 2nd check for a gingival flare, 3rd discuss with your veterinarian to suggest a plant based digestive enzyme for your cat with every meal, 4th check with your veterinarian to determine if your cat's vomiting is actually due to food sensitivities.
If this is the case, the food sensitivity comes from a hormone antibody imbalance. You can read about doing the proper blood test to determine this and stop further food sensitivities by checking the other articles on this web site, but please realize, even if you purge your cats system from this food for months, the immune cells will still continue the reaction that did occur from before.