Honestly, my opinion is that sometimes it's just something they do and there is no good explanation or reason for it. Our cat did this starting at about the age of 4, and continued until he passed away just recently at 12 years old. Over the 8 years we did all kinds of medical tests, made all kinds of changes based on suggestions from other people, yet nothing ever changed the behavior. He did slowly progress from pooping more frequently just outside the box to pooping in other places in the house. As he got older he clearly had some issues with dementia, and this only magnified the problem. He had always had behavioral problems, and honestly sometimes I think this was also his way of acting out. Best of luck to you - I hope you have better luck than I did!

Have male and female Female (Mouse - yes thats her name lol): 3 1/2 Male(Lil Bit): 1 1/2 Each have their own litter box but will go in either one. they get along fine - NO fights (but they like to have sex a lot- LOL) - but Lil would pee on couches, couch pillows, hall wall-to-wall carpet and NEW cement covered with vinal tiles, my bed (other side where no one else sleeps) and my pillows. got him fixed when he was 9 months old - 1st mistake - shoulda had him fixed as soon as possible I started all cats that have been in my home the same way, in my bedroom for about the first week, then moved litter across the hall to bathroom for about another week or two (and keep BR door closed), then down to the laundry room (and keep Bath door closed). Showed them where the boxes were each move and all was fine, sharing three boxes, 2 in the laundry area and one kept in my sons BR in basement ...until this cat.... The move to the basement was fine, he didnt go an pee anywhere but down in the basement. Then after about a month or two he started to pee on my couches. then the hall between my bedroom and the bathroom. then in March of this year until September, both cats had to have their box upstairs. They share it fine. It gets cleaned out every other day or so. Neither is insistent on a daily clean of the box because sometimes I'd like to go away for the weekend (leave Fri and come back Sun) so I wanted them trained to not have a pristine box. Oh, and its huge with a cover. neither will use it without the cover. so during March-Sept 2013 ... the box was under my dining table which they used. My basement was being entirely being redone. Understood this activity would get on their nerves. I hated waking in the morning, opening my Br Door only to step in pee.... Lil still peeing in the hallway and on my furniture. so as soon as the basement was finished, Mouse stayed in basement BR with my son, and Lil Bit stayed in laundry room... (new walls, paint and cement floor) - sometimes with Son putting both cats together. They had a large box with towels for bedding which they shared no problem. The idea behind this was to re-train Lil Bit into using his box all the time. I went down several times a day to give him attention too...he's a cuddler :) After 3 weeks, I opened the laundry door to the rest of the basement... also completely redone with new cement floor and vinal tiles. After a week of this extra freedom and demonstrating the continued use of his litter box, I opened the basement door for full house reign, including my bedroom. Within one day, peeing on the couch and pillows started, also Peed on NEW bed mattress and NEW pillows (had to have pillows thrown out- no bedding was even on the bed yet) and washed and turned the mattress over. (kept the door closed since) Cleaned out the main litter box, washed and cleaned all floors and then he peed again in the hallway. Seems to be about once a week he does that. I have concluded that: 1. A clean litter box does not make any difference. Lil will pee upstairs even if I have JUST cleaned out the litter box. 2. There has been no changes in my household other than the re-construction in my basement and Lil was peeing all over before that anyway. 3. NEW vinal flooring getting ruined. 4. He has been to the vet and does not have UTI or even partially crystallized urine. 5. Mouse is the perfect little lady. She does not mess anywhere but in the litter box. I have read a lot of posts with issues... but no real answers... oh and the shoving their nose in it does work some of the time...only if you catch them and do it right away, then take them to their litter box. I had to do Mouse (and previous cats) this way and she never messed again... and neither did the other cats. Just Lil Bit... such a heifer too... got fat after getting fixed. They are both NOT declawed either. Mouse is a mix with calico-like coloring and a tiger face. Lil Bit is a black long-hair and 12lbs. So... maybe try Prozak or the like with him?

https://www.gardenweb.com/discussions/4905066/cat-litter-suggestions-needed?n=30

I'd like to thank you all for your thoughtful responses. I just placed an order for The World's Best Cat Litter that Lucille mentioned above. I think we'll try a opaque tote with a top entry cut into it. At least we can cut a front entry if the top doesn't work out. Most of the dog shenanigans occur when I am sequestered in my office working and my husband is at work, we keep the box fairly clean and scoop almost every day but only once. When we are working, they take advantage or maybe act out because we've left them alone. I'm just hoping to cut down on that.