Thanks for all the comments. I had a crib mattress in the garage and brought it in for him to try. He commenced a three-hour nap almost immediately. :) It's a little small, and he didn't sleep on it over night last night, so we will continue the search using many of your other constructive pieces of advice. I'm liking the memory foam toddler bed and the Costco $65 orthopedic dog bed suggestions the best right now.
Regarding his weight. OK, here's the deal, and you can tell me your opinion afterwards:
To the best of our knowledge, he was born in the summer of 2000, in a Labradoodle puppy mill outside of Houston that was shut down by authorities.
He escaped wherever he initially wound up and was found by a municipal dog catcher on the access road of an interstate freeway. The pick-up record had the comment "control personnel assisted dog from imminent death by vehicle."
He was placed in a municipal kill shelter, where my three daughters found him. He was dirty, matted, had heart worm and was a large, pitch-black mixed breed. His chances weren't good at all, but my three daughters fell in love with him and we rescued him. This was in the summer of 2002 and he was estimated to be two years old by the vet. The vet also pegged him for a labradoodle and told us about the nearby labradoodle puppy mill that was shut down. She had seen multiple dogs that had come from that mill, and immediately recognized our dog as one of them.
As the only other male in the family, he's been my dog since day one, and we have had a wonderful 13 years together. He's sitting at my feet right now as I type this. He's been an amazing dog. He's never bit anyone, rarely gets annoyed, is quiet and obedient. He loves chasing rabbits and the UPS truck. He's one of those dogs that when we go to the dog park, people just can't get over how fantastic he is, especially given his age. He'll easily still get more attention than most of the pure breeds, and always has.
His weight - He's always been big. Much more black lab than standard poodle. He's been as high as 135 pounds. Our current vet is actually very satisfied with him hovering just over 100 right now. He is on Perscription Diet W/D and has been for years and years. Even though we are broke right now, we continue to have our dog on that food. He does get some table scraps, a tradition that dates back to him helping me raise three elementary-aged girls all the way to college. We go on a off-leash walk EVERY evening around 10:30pm for about thirty minutes - a tradition that dates back at least six years. He chases rabbits (much more slowly now) and the walk is the highlight of his day. We keep him 'field cut' with no curly hair except on his head and face. That keeps him much cooler and cleaner than the alternative. He has always been very healthy. At one point I took him through a four-week agility training course, and even though he was twice the size of most dogs there he did well and seemed to really enjoy it. His biggest medical issue throughout his life has been ear yeast and ear infections.
He's slowing down - very noticeably in the past few months. He sleeps more, his hearing has diminished, and he occasionally loses his appetite (something that has never happened before). He has a hard time getting up off a slick floor and his back legs seem weak. Always sure-footed, I've noticed him trip and slip lately. Back when I was more financially secure, i bought him that fancy dog bed you see in Skymall from the airplanes. It was over $200. But it's used up and there's no way I can afford another right now. .....So that's what brought me here with my OP.
News flash: Large breeds don't do that well past their 15th birthday. He's been on significant diets before and he doesn't like them one bit. He's weighted as high as 135 and now is around 105 or 110. He's seems to be really slowing down. After all of this, is the advice to restrict his diet even further than the Prescription Diet W/D? Thanks.