Hi,
I'm sorry to hear your cat is not feeling well!
Foaming at the mouth/excess salivation can be caused by a variety of reasons. Has the vet checked his teeth/gums/mouth/tongue for any abscesses or sores? Sometimes tonsilitis can cause excess salivation. Is he having any trouble swallowing and is he gagging or coughing a lot?
When a cat is nauseated, he will start licking his lips and may salivate. If he's throwing up a lot, something may be nauseating him. It's possible that he's allergic to an ingredient in his usual food, so I'm glad his food was changed to something that's easier to digest, but the same ingredient or ingredients may still exist in the new food and may be causing the same symptoms.
Is there any chance he could have gotten something he shouldn't have, in his mouth, and chewed on it or ingested it? When cats taste something they don't like (or a toxic substance), they will drool excessively (causing the foaminess you witnessed) in order to try to wash the taste out of their mouths. Is your cat taking any medication at this time? Is he on any monthly flea preventative like Advantage or Frontline?
Did the vet test a fecal sample for intestinal parasites? Did your cat receive an injection of an anti-emetic to stop the vomiting and was he ever given an injection of something to settle the stomach? Was acid reflux considered as possibility? Did your vet suggest giving one tablet (or a portion thereof) of Pepcid AC, daily or a few times a week?
What food is he eating now?
Do you ever feed him cow's milk? Most cats are lactose intolerant and will develop digestive problems if fed milk.
Hill's i/d is often prescribed for cats with vomiting and diarrhea to help settle the stomach, because it's very bland. You can also try some jarred chicken baby food (with nothing added except water or broth--no spices, especially no onion--check the label), since that's very bland, too. You can try feeding some plain, skinless, boneless, boiled chicken breast mixed with overcooked plain white rice. Purée it slightly in the food processor. You can also try adding 1 teaspoon of plain, unflavored yogurt to some canned cat food, daily, to add 'good' bacteria back into his system.
I hope some of my suggestions prove helpful and you're able to discuss some of these possibilities, if they haven't yet been discussed, with your vet, to try to find a solution to your furry boy's digestive problems!
I hope he's feeling better very soon. Please keep me updated. Thanks!
Cher
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