Good luck with Pete, I too would be interested in what the vet has to say. The only time I ever saw this was with a 7 year old Boxer that had a bladder infection. The incontinence stopped after 2 days on antibiotics (although we finished the prescription just in case).
If it is just "leaking" from old age or another cause you might check out getting some "belly bands" for him. These are strips of fabric that you can wrap around his middle to soak up the urine. My mom uses one on her older male Yorkie and uses a pantyliner inside the belly band to soak up the urine, then it's changed when he goes outside to potty and as needed and to freshen him up.
Teresa |