dehydrated cat no better after seeing vet

A couple years ago my cat had a spell of vomiting, lethargy, and dehydration, and after several tests it was assumed she had gotten into some chemicals.  She seems to be going through the same situation again.  Friday afternoon she started throwing up, and after 4-5 times we took her to the ER vet late that night.  We had them give her fluids under her skin and some anti-nausea meds to make her more comfortable until we could see her regular vet.  Saturday morning, we took her in and they did an x-ray which revealed nothing, and they are doing a blood panel which should have the results in tomorrow.  Last time, they gave her IV fluids and kept her overnight, but by the next morning she was feeling much better and decided she didn't want to be there anymore (i.e., was not a very nice patient).  This time they chose not to do the IV and just gave her more fluids under the skin and a stronger anti-nausea med.  This was yesterday morning around 10, she threw up one time in the afternoon (after I showed her some wet food, and she seemed to sniff it, then get sick) and I did catch her urinating in her litter box in the middle of the night.  Aside from when she's vomiting or the one trip to the litterbox, she will not really move.  She's laying in the same spot on a pile of my clothes, and she won't look up at us when we enter the room or pet her.  After she has gotten up to throw up or use the litterbox, she will go hide under the bed for awhile, then return to her nest in my clothes.  She's very lethargic, and nearly limp if you pick her up.

Since it is Sunday, the only place open is the ER vet.  At this rate I'm thinking I will bring her back into her regular vet tomorrow morning because she's obviously not feeling well.  I'm concerned because last time she was perking up by now, but maybe that's because of the IV she had then.  Today she still has no interest in food or water, but I'm more concerned about the water.  Will she be ok to go a full day without fluids?

[Aleda M Cheng, D.V.M., C.V.A]

She should really have the IV fluid therapy since that is what helped last time, and I believe that it is probably imperative that you discover what is causing these episodes of vomiting, anorexia and lethargy.  Perhaps you could ask your vet to test for Feline leukemia, Feline AIDs, Bartonellosis, and some of the less common infectious diseases, (if not already tested).  

[stephinchicago]

Thanks for your response.  She continued to vomit last night and this morning.  We took her into her vet first thing this morning, and her blood tests were pretty normal, other than showing that she was very dehydrated.  They thankfully decided to keep her and do IV fluids, however they are now suspecting that she has a bowel obstruction.  So poor kitty is having a barium series right now and may be in surgery shortly.  :(

I'm rather confused/mad about why they bothered to do an x-ray on Saturday instead of doing the barium test upfront.  We saw 2 different vets, and the woman on Saturday said they were concerned about obstructions and recommended the x-ray...but the dr. today said that x-ray won't really show an obstruction and a barium test is needed.  So what's the point of the x-ray they did, and shouldn't they have done the barium test earlier?

[Aleda M Cheng, D.V.M., C.V.A]

Survey X-Rays can sometimes show obstruction patterns if you are lucky.  A barium study takes many hours and sometimes overnight so it would not have been possible to have a barium study performed on Saturday unless it was at a emergency clinic.  They are also expensive.

Barium studies are rarely performed "up front" unless the pet was actually seen ingesting non-food items that can cause obstructions, or has a history of ingesting things that can cause obstructions.