cat gets sick around other cat

Hi everyone, this is my first post so sorry if I break any rules. Basically I'm a new cat owner and have two cats each about 6 months old. I got both cats from the shelter last Saturday (the 3rd) and both cats are great. However, one of the cats is terrified of the other cat. So much that he drools everytime he sees her, he doesn't try to hide he just drools. If I don't put him in a seperate room he will vomit. It's gross, but also I worry about him getting dehydrated. Around me he is fine, but I don't know what to do if I put him in his own room he cries, but if I put him out he drools. Any advice to get him used to her?

Welcome to the forum!

From what I understand from your story, you just adopted 2 young cats, of which one vomits when close to the other, but doesn't when they are seperated. It sounds to me like that that one cat endures a lot of stress when seeing your other cat. This causes him to drool and vomit if not seperated.

I think you need to seperate them and introduce them slowly, if you haven't yet (I just saw your post, but it seems that you posted it 3 days ago already) It's best to keep one cat in one room, and another cat in a room/place that is near it. So they can smell eachother through the door. They will get used to each other's scent and after a few days, you can introduce them to each other face-to-face but make sure you stay near it. See how your sick cat reacts to the other cat. If it seems to go well, but you are still unsure, you can seperate them again after. At least they saw each other and if the one cat didn't got sick he will eventually learn that he doesn't need to feel stressed when meeting the other cat. Eventually you can let them share the house and no longer seperate them.

If this doesn't help, feel free to let us know so we can help looking for another solution again.

Also, feliway might help you as well. It's something that makes cats feel more at ease, helps well with introducing cats to one-another too.