12 y/o cat eating cat litter

Firstly, I know it's not healthy for a cat to eat cat litter so I have removed the litter box.

This is a 12+ y/o outside cat who stays in my garage during bad weather. I took her to the vets just a couple of months ago and I was told the blood work was ok except the BUN was about 59 and creatinine was only slightly elevated at about 2.4 or 2.7, I think. The vet noted that the mucous membranes were pale but I guess the blood work didn't show any signs of anemia since it wasn't mentioned to me.

Is there any reason why a cat would eat (clumping) cat litter? I have no idea how long this has been going on. I just happened to see her eating it one night. This is the only strange thing I've seen her eat. I guess I should call the vet but I definitely don't want to have to take this cat in. She's lived outdoors her entire life and last time I took her in she bloodied up her nose fighting to get out of the carrier on the way there. I was hoping I could bring her inside to live but that can't happen if she's going to eat cat litter.

Anemia will make cats eat cat litter.
She needs an exam and blood work done to find the underlying cause. This article gives you excellent detailed information:

http://maxshouse.com/anemia_in_the_cat.htm

It's definitely not normal for a cat to have pale gums/mucous membranes. This is a sign of anemia. The Vet shouldn't have just overlooked this. Wonder if the bloodwork done included a basic CBC (which would show anemia; low red blood cells, low hematocrit (aka PCV/packed cell volume), low hemoglobin.

And yes, anemic cats will often eat litter. This poor kitty needs to have the cause of anemia determined.

Cats with kidney failure often develop anemia in later stages but if kitty's Creat wasn't all that elevated, it's not likely impaired kidney function causing the anemia.

Some common causes of anemia in cats:

-major flea infestation
-feline infectious anemia (FIA); caused by a bacterial infection in the blood. Here's a link with info on it along with how it's treated:

http://www.fabcats.org/owners/anaemia/info.html

I wonder if trying a different type of litter might be worth a shot? Or even using shredded strips of newspaper or something made with wheat or even those litter pearls. something makes me think that anemic cats like to eat the clay-based litters but don't quote me?

I'd seriously reconsider returning to a Vet who disregarded pale gums.

If it was me, I'd be requesting a copy of all previous lab work done on kitty.....then taking it to a different Vet; advising that kitty is now eating litter, you're concerned about anemia.

You said her blood work came back ok? Has she been tested for FeLV? Someone else mentioned some common causes of anemia, but FeLV is also one to look into if she hasnt been tested yet. I had a kitten die from leukemia and I first noticed something was wrong because I found him eating litter. I looked at his gums and they were whiter than ever. He was severely anemic and the vet said it was caused by the FeLV . I would definitely try another vet though. It really does seem odd to ignore the pale gums. Good luck...sending your way.

have her teeth been checked? What is she fed? What type of litter is she eating? clay or a natural kind?

When adult cats start eating cat litter they are sick. This cat needs to be checked out again by the vet. Speedboat started doing that back in January.
He was in renal failure and is gone now. Please take him on and find out what is wrong. There is a litter called Yesterday's News made of paper that you could use until you get the cat to the vet. Keep us posted.