My cats (sisters-both spayed & 2 yrs old) we don't know which one is doing it. We give them sooo much love and affection, they even have their own room on the main floor with 2 litter boxes always spotless with same litter since they were little. I noticed the last couple months on our bedroom carpet a few feet from their room we have been smelling cat urine and once in awhile step in it (yukky)neither has urination issue - been to vet, can't figure out what's wrong, clean/same litter/no stress known to either of us, no kids at home, rural area with little or no company, tons of toys and play time, they love and get along great together???? Any suggestions? Thank you.

Aside from the subscribe link not working, It has been my personal finding that litter problems are associated with the following problems
1. Smelly cat box scooped or not.
2. Territorial problems involving clawed and de-clawed cats
3. Illness
with the odor problem being the worst by far.