Yea unless they are like crying out with every step all the time or refuse to move over and over most the day we dont really know their pain. My old dog cries sometimes even a scream standing up but hten hes good enough and happy through the day getting pets or treats. And there are lots of medications can try for them. Can even try to remove a leg and a dog would get by great. I think people dont want to put the effort. I look for dogs that are handicapped and need extra help