I'm worried about my cat

OK, I've got two Siamese cats. Had 'em for 9 years now. They're sisters, from the same litter.

Go ahead and laugh, if you must. But, it's true: I have a set of Siamese twins running around my house.

Well, at least I did until today.

One of them is having a problem getting up and down the stairs, and I'm worried about her.

I mean, I know she's not a kitten any more. But, her sister isn't having any trouble.

And, tonight, I had to practically force her to drink some water. She wouldn't touch her food.

So, that's why I'm worried.

Taking her to the vet first thing tomorrow morning.