Vomiting and Weight Loss

I have a puzzling problem here, ever since I had Oreo to the vet 1 month ago for FLUTD and was given prescription food for him, the vet said my other cats could eat it as well. Anyway my one cat Snoopy who was fairly heavy for some reason has refused to eat any of this food and as a result she has lost some weight and keeps vomiting up spit. Any thoughts?

I would say kitty needs to go the vet. Vomiting a lot is a concern and vomiting liquid is a larger concern than vomiting just food or hair. Please take kitty in to be checked.

allergic to something in the food. I would take her to the vet right away.

Anyway took Snoopy to the vet this morning, definetly was dehydrated and she had lost 2 lbs. Vet couldn't find anything physically obviously wrong with her. Gave her an anti nausea shot and a litre of water by IV. Trying this first before doing something else. Vet said if this doesn't solve it, it's quite likely her liver or kidney is malfunctioning.

You should try putting Snoopy in a seperate room with a bowl of his own food a few times a day. Not eating could also affect his kidneys and liver.

That's a good idea, not easy in practice though...... I guess I'll have to wait until she comes out of hiding and I'll have to toss her in the bedroom for half a day. Tried hand feeding her lastnight to no avail.