My 16 year old cat (female) started eating her litter from her litter box (yuk!). How do I get her to stop? Tried different litters-no avail. The vet ran blood tests etc. and other than the fact that she's elderly and her bodily functions are slowing, he had no advise on what to do about her strange behavioral problem. Does someone have some insight to this? Eating litter just can't be any good.