Very sick cat

Poisoning?? Did she/he get into some rat poison or antifreeze?
Sorry I can't be of much help and I hope your cat is doing better by tomorrow.
.

I was thinking antifreeze, too, but the vet should know. The antidote for antifreeze poisoning is ethanol ( e.g. vodka) but it might be too late for that by now. I would call and talk to the vet. Hope kitty gets better.

I would call the vet back right away. Don't wait for it to get worse. Tell him she is worse instead of better and they you believe it is an emergency.
Is it possible that she could have eaten chocolate, onions, or gotten a hold of some type of Christmas decoration like tensil? That happens alot this time of year.

Has she had all of her shots, wormers, etc.?

I would call the vet as soon as possible.
Hope she gets well soon.

Thanks for the comments and ideas. Sorry to report the cat died at 2 am this morning of undetermined cause. FB

Sorry to hear that! I'd maybe look for another vet!

I am very sorry about your cat.

I'm sorry.

I'm sorry about your cat.

When you feel like it, I'd still check for a source of poison in case there's other pets in your household.