Yeah that would be same day for me, and I’m a very “wait and see” kind of pet owner. If either of my cats skipped a meal, I would be immediately suspicious of something being wrong.

My cat is 11 and diabetic. His meds are a liquid oral that can cause ketoacidosis so if he vomited 2 times I would be on the phone with his vet. Full blood panel, ketone check, if those are clear/within normal levels I want an X-ray to see if he mistakenly ingested a foreign body he can’t pass. I also, due to his meds being high risk, log all his litterbox uses so we’re bringing a stool sample with us (parasites?) and doing a urinalysis (check for blockage, uti) to be on the safe side.

Id think right away, but if it's an old cat a person may need an extra day or so to say good bye. In my experience.

hours; probably after the 5th vomit in a few hours.

Minutes. Literally minutes. As long as it would take me to get the cat in his carrier and haul that down to my car. A cat like that is SICK, possibly poisoned, and needs emergency supportive care right away, not hours or days later.

All red flags. My cat would be at the emergency ER immediately.

I wouldn't wait any longer.

Time to go! Don’t risk it

literally within the hour.

The minute I notice something is wrong