I checked to see if she had actually used her litter box since I had cleaned it last night, and there was nothing in there. I prompted her to use it, and she had very runny diarrhea, so I immediately called the vet and got her in. She also wasn't eating her dry cat food (the canned food she scarfs down). She has a viral infection and the vet said it's a good thing it was caught early since young kittens are so susceptible to this type of virus.

So she has some medicine for her diarrhea and antibiotics, plus some wormer medicine just in case. She also recieved a sub-q as she was getting hydrated. He said to keep them segregated until Abby is feeling better and we'd touch base on Saturday when I take Suki in for a checkup and shots.

They are both spayed; Abby is 4.5 months, Suki is 3 months. Both were adopted from our area Humane Society. I dearly hope that Abby's actions were caused from her illness; when Nina was alive, Abby was clearly the dominant cat but she did get along with Nina, so I'm not sure if she is a "one person" cat.

Thanks all for your advice. I'll keep you posted as to our progres. Please think happy thoughts for us!