Did anything in the home change when she started doing this? Schedules, people, anything to do with the litter?Our female, 4 year old calico had recently begun to pee on the bottom of the stairs. Doesn't matter that the litter boxes are clean. No UTI or other illnesses.
I'm sorry about your mom having to leave. If it started shortly after she left it could be connected. Is there any way the cat could visit your mom on occasion in the nursing home? I'm not saying that would fix it, but your mom might enjoy it.....My mum was moved to a nursing home.
The litter type is changed frequently.
She does this during the night usually. If during the day, it's when no one is in the room.
It's downstairs. The litter boxes are in the enclosed patio.
The two male cats always use the boxes. There are 4 litter boxes.