At wit's end with cat

My cat, Cricket, is driving me nuts. I started a thread about a month ago about my younger cat, Yeti, who has actually gotten a lot better. But Cricket is our older cat and she's about 10 months old. We've never had a problem with her. The day we brought her home she went straight to the litter box and has never gone anywhere else. About a week and a half ago, she pooped on the carpet in the dining room. We figured that the litter box was too full so we cleaned it out and sprayed the carpet. Two days later she did the same thing. Then she started peeing on the carpet, too, even when the litter box was almost empty. We figured she kept going in the dining room because the smell must still be in the carpet. Well now after we steamed vacuumed the carpet and even got another litter box for the dining room, she poops right infront of the litter box or around it. I think she might not want to go in it when our other cat has used it, but I'm not sure. I've even scooped up her poop and put it in the litter box so that maybe she would recognize her own smell. I'm really tired of cleaning up poop, especially when we already have 2 large litter boxes. Any suggestions?

Yes, please take your cat to the vet ASAP to rule out any health causes for the inappropriate peeing & pooping.

Then try changing the brand of litter that you are using - sometimes that does the trick.

Yes, go to the vet to rule out any medical issue.

You might try changing the litter to cat attract (some folks swear by it). When you said you thought the litter box might not be clean enough, I'm hoping you scoop a minimum of at least once per day and empty the old litter and wash the box on a regular basis as well.

Some cats are very fussy about not using dirty litter.

Also, I'd try adding another box... if she doesn't want to go where the other cat has gone, an additional box might help?

Sometimes medical issues crop up and cause a cat to begin associating the pain of an illness with the box. Even once an illness is cured there's the psychological battle of convincing your cat that the litter box isn't evil. That happened with one of my cats but luckily he's the world's biggest glutton. Treats on the back of the box (he had to get in to eat them) soon solved the problem, after he was well, of course.

Then again, your cat may be perfectly healthy and may have decided not to share her box with your other cat. A third box in a different location and with a different type of litter may be all you need.

Good luck!