A cat that doesn't groom itself may be sick or have some sort of psycological problem according to my vet. Your friend should get it a check up to be sure. I too have a nasty cat. Her health is fine, but she's always been gross for some reason. When we got our second cat, she finally started looking clean. We thought the new cat had taught her grooming habits...Until we caught him cleaning her one day. lol. I guess he didn't want to hang out with a nasty cat.