I just went through all that with Leo. He's 2.5 yrs old and has been potty trained since he was very young. A couple of weeks ago we were sitting on the sofa watching tv & he pee on the blanket that was on the sofa
After that he started peeing everywhere in the house. I had no clue what was going on. But I also noted that he looked kind of sad all the time, never lost his appetite though. I took him to the vet & sure enough he had calcium oxalate stones in his bladder. He had surgery 3 weeks ago & is doing great. No more accidents!!!! The only problem now is that he has to be on a special diet. I have 2 yorkies & is kind of hard to feed two different diets. I suppose to take him back to the vet in a couple of weeks so he can check his urine again. Will keep you posted. I hope Lucy gets better.