Vomiting cat. What can I do until the vet?

Hi everyone, 

My cat started to vomit a couple days ago. I was deworming him last weekend, and first I thought that it is simply a side effect (he had it last time), but it seems to stick. 

Since it seems to be really bad, I already called the vet, and I have an appointment for next week, but I feel so bad for him and I would love to do something for him, until he gets professional help. 

At the first days he puked a lot, I found like 6-7 from one night all over the house. After that he started to lose his appetite, and with that the vomiting also started to become less. Today he didn't puke at all, until I gave him food. He seemed to enjoy eating it, and I already thought that he is getting better, but 10 mins afterwards he started throwing up again. He seems to be sad, and depressed, not so lively like normally (although he is very calm cat generally), less interested in playing. So very typical sick behaviour.

Oh, and another important info: I have another cat, who is most likely pregnant (not sure yet), she is entirely fine.  This would make it harder to withdraw food, but of course if that's a solution then I can solve it. 

I am really worried and I am not really sure what to do... did anyone experience something similar already?

Any suggestion what I could do to help him? I would really really appreciate any ideas! 

Have you checked he's not getting dehydrated? (Do his eyes look sunken/can you see his third eyelid? If you lift a pinch of his skin is it slow to ping back? Is he listless? etc). It won't do him any harm to miss a few meals (probably better not to try to feed him until he's seen the vet and you find out why he's being sick), but he needs fluids. If he's vomiting a lot and you think he's not drinking (or not keeping down what he does drink), then you need to contact your vet urgently. He may need IV fluids. In any case, if you're worried, best thing is to talk to your vet on the phone. They'll advise you if you need to take him in more urgently, and/or give you advice on what to do until you see them.

Sounds like he is not feeling well. I think you should call your vet, let them know he is ill and see ig they'll let you come today or tomorrow, not much longer than that.  You could try resting his tummy for a few hours, no food but let him have water then seeing if he can keep down cooked, boneless, skinless chicken.

Thank you for the answers! 

I am not a 100% sure but looking at the symptoms, he doesn't seem to be dehydrated. Except for the lethargy and vomiting, the rest looks good. 

Now he just ate again, and I am waiting whether he will be able to keep it in. 

I will call the vet tomorrow and ask for some advice or see if she thinks that I should bring him in right away. 

My biggest concern is that I actually don't see him drinking. I almost never do anyway, he likes to eat and drink when noone watches him, but now of course I am constantly monitoring him and see nothing. 

Is there a way to get him drinking to be sure that he took some fluid? I'd try put him in front of his water bowl, but being a cat he simply walks away.. some things don't change even when he is sick  

Can you try tuna water that comes from a can of tuna packed in water? Also, are you sure he is urinating?

I will try that!
No sadly there is no way to be sure that he is urinating. They are using the same toilets and I can't possibly know whether there is urine from both of them.

Okay, can you separate them for at least a half a day and see if he is urinating? It's important to know for sure. Another question, is he eating possibly too fast? What food were you feeding when he vomited it back up?

unbelievable but he stopped vomiting since yesterday. 

When I wrote for the last time, he just ate and it seemed that he could keep it down, and also no problems today either. 

He eats nicely and I also saw him drinking twice today. Also he went to pee as well. 

It's like he was never sick at all. 

Really weird... 

Glad to hear he is well. I was worried about him. Maybe he had a hairball or something?

It might have been a bad reaction to the dewormer you gave him, since you say he had side effects from it before. Maybe once he got it out of his system he was able to recover.

@momto3cats  Has a very good point, maybe you shouldn't give him that dewormer anymore. What kind is it?