The kennel where we adopted our sled dog Velma had a dog that lost his eyesight, but was such an energetic puller that they kept him on the team. This was only possible because he had a loyal brother who looked out for him. So, the mushers learned to always pair Gonzo who was blind with his brother Poncho as they harnessed the dozen dogs to the sled. Whenever Gonzo veered off the course or fell off the edge of the packed down trail, his brother would grab his harness and pull him back into his proper position. This kennel allows all their senior and disabled dogs to remain at the kennel to at least enjoy each other's company even if they are no longer able to pull. They offer them for adoption, but only to caring owners who will accommodate their individual needs & behaviors. Here's a photo of Gonzo & Poncho.
I believe all dogs and cats who are OAP's and disabled deserve happy homes to live their lives out, at the end of the day they will give love and companionship to their new families just like young and able bodied pets. Every animal deserves a happy home unless it's in pain or is dangerous and could cause harm to people.
Yes, the pain part is hard to determine because pets are so loyal. I once built a wheeled contraption for a friend's dog that got hit by a car and lost use of its hind legs. The dog managed to get around, but was not truly happy or independent and became incontinent so the owner made the hard choice to have it put down. At least we all tried, and the dog knew that its master loved him. I have had to put a couple dogs down and it's the HARDEST thing. But I keep on adopting new ones.
It is nice when you can help a pet out that is in distress or just needs someone to help it out in anyway that there can. Even if a pet has a disability there sure should get to live a happy life as mobile as possible.
I recently saw a video of a little dog who was born with no legs, he just has little stumps (I think he's in Vietnam) but it was amazing how he could get around by wiggling his stumps and he actually moved quite fast! Then a veterinary hospital that specializes in prosthetics for animals made him a wheelchair which holds him up off the ground and he walks on his stumps and pushes himself around! Then an animal welfare organization heard about him and installed a special ramp at his owners home so he can go in and out on his own and they set up a room in the house with a padded floor and a fancy bed! He's so cute and it was so wonderful that people gave him a chance and didn't just put him down at birth! Animals are much more resilient than humans, they don't complain or feel sorry for themselves, they just get on with life and as long as they are loved they are happy!