cat being sick 3 times a dy lots of water lately

Question
Hello our cat is a black standard cat. has been being sick -not just furball since the last  3 months. she has always been a bit of a pig overeating and being sick but now she is sick 3 times a day since for about 3 months. We have had had her on dried food royal canin, then tesco the back to rc. we found she held down wet food better.We have taken her to the vet who said she had lost a lot of weight , kidneys small but nothing to worry about, bloods were all ok inc kidneys. she said the next step would be xray and scans but as this is so dear we thought we'd try her on different wet foods . she was ok for a cople of days but then has started vomiting water twice now in large quantity almost projectile in  four goes.she is off her food after some pate type earlier today but is listless and hang dog tonight hiding away a litle bit. we don't want her to lose more weight and keep trying her on tuna which she loves but not tonight either. any ideas gratefully received.

Answer
First thing you need to do is stop changing foods. That is only making her sicker and sicker. She may have early stage kidney disease or even liver disease. You said her blood work was normal, however, how long ago was that?

Cats that don't eat are prone to developing fatty liver and especially when they were fat and lose weight quickly. This is compounded by her eating different foods all the time. That upsets her stomach and her liver and pancreas.

You should get her on one kind of food- something of high quality such as Science Diet light which as less fat in it, or the sensitive stomach formula.

Then keep her on that alone. If she won't eat it, mix some of the wet of the same brand in it for a few days or just feed her the wet.

Either way, she needs one diet and one diet only. Other wise she will continue to get an upset stomach and vomit.
If the vet wants to scans or xrays opt for the scans as they will show more for the buck. But at this point you mostly need to get her settled down with the vomiting.

Normally I would suggest a 24 hour fast to calm her system but not for a cat. So if nothing else then I would get her some lamb and rice or just rice baby food and give her bits of that until the vomiting stops- just so she has something in her stomach.

But you need to put away the tuna and the other foods and stop the food switching.

If she continues to vomit you really need to have a better work up done on her. I don't know how old she is but age is a factor in kidney and liver disease.