multiple cats are sick

Hi everyone, sorry in advance for the long post.  My fiance and I have four cats and three of the four are vomiting.  The first one started a few days ago and has not eaten since Thursday.  We took her to the vet friday where they found out she was backed up quite a bit so they gave her two enemas and anti-nausea medication. She hasn't thrown up since then and still won't really eat although she did just have a small bit of tuna.  The other two that are vomiting started a day or two ago and they haven't eaten in a day or day and a half.  There has been no diarrhea and no blood in the vomit.  We have no idea what to do.  The fourth cat is just fine though. Are they are any suggestions as to what this might be? They are all strictly indoor cats and we have been feeding them all the same food for awhile now and the bag of food we're feeding them is the end of a bag they've been going through for a month or so.  We have no new items in the apartments. Any clues? We will of course bring them to the vet but we just want some direction. Can anyone think of something that would make three out of four cats sick? 

First and foremost, the 3 need to be seen by your vet, today if at all possible. if not, first thing in the morning.

Not eating for more than 24 hrs can lead to a condition called Hepatic Lipidosis (Fatty Liver Disease.) They may also be dehydrated, which can lead to constipation.

Perhaps their food is stale? Have you put any topical flea meds or anything else on them? Any plants in the house?

Can you get some Gerber stage 2 Chicken&Gravy or Turkey&Gravy baby food? See if that entices them to eat.

CatPack said:

First and foremost, the 3 need to be seen by your vet, today if at all possible. if not, first thing in the morning.

Not eating for more than 24 hrs can lead to a condition called Hepatic Lipidosis (Fatty Liver Disease.) They may also be dehydrated, which can lead to constipation.

Perhaps their food is stale? Have you put any topical flea meds or anything else on them? Any plants in the house?

Can you get some Gerber stage 2 Chicken&Gravy or Turkey&Gravy baby food? See if that entices them to eat.

Click to expand...

We are calling our vet tomorrow.  The first cat which we brought to the vet on Friday was surprisingly not dehydrate.  To answer your other question, we've tried wet but two of the cats still won't eat. No topical meds and no plants in the apt.  We have nothing new in the apartment. None of the other animals (and we have a few) are sick at all. 

Perhaps they ate a bug and this has made them sick?

Often cats that don't eat typical canned cat food DO eat the Gerber baby food. You could also try some low-sodium chicken broth.

CatPack said:

Often cats that don't eat typical canned cat food DO eat the Gerber baby food. You could also try some low-sodium chicken broth.

Click to expand...

They normally have no problem with the canned food.  It's the same canned food, different flavors, for over a year now.  We can try the chicken broth idea though.  We're just worried since we have no idea why three of them would get sick in different intervals though. It's strange.  

CatPack said:

Perhaps they ate a bug and this has made them sick?

Click to expand...

You mean a literal bug? Possibly but one of the cats is the biggest wimp ever and would run away from the site of anything that crawls around.