I am so sorry for you loss. It's terribly hard on us when they have to leave, isn't it. My Boo grieved hard for Annie B when she left. I was blessed to be able to bring a puppy into our home within a few weeks. Boo gave her the cold shoulder for the first day or two. But Gracie Ruth quickly won him over with her tom-girl charm. Boo was 5 when Gracie Ruth joined us. But I'd be concerned that at Rudy's age the none stop antics of a puppy may be too much for him. Perhaps an 'older' young dog would fit in better. One that's between 1-3 years. Still young enough to have that youthful enthusiasm, but old enough to not be puppy hyper. Good luck with your search, keep us posted.