I ' m another vote for kitty diapers . The only downside is that they really should be changed very soon after being soiled to keep the cat ' s skin from getting urine burns . You might also pick up special cat cleansing wipes to clean him . Since you have a kid , you have some experience with the diaper drill . If he has favorite places to sleep , you can put some waterproof sheets down to protect against leaks . We get them at Walmart in the bedding section . They can be laundered , and last a long time . You can cut them to size , if you need something smaller than a sheet . You might consider a quick vet visit . It ' s possible that he just has a urinary tract infection that could be cleared up with antibiotics . Not super expensive , but not free , either . I ' m sorry your buddy is having this trouble . He ' s lucky to have a lifelong friend to be there for him in his old age . Good luck !