I watched the hunter trot toward the back gate and I realised that he was walking like an old dog. It's hard to describe exactly what has changed, but he's slower to start moving. He no longer springs into action. His muzzle is white underneath now and those pale hairs creep up the sides of his face. He noticeably pants from pain, from time to time and his hips sometimes click as he walks. When Lady Snoutingdingle walks him, he will often stop or slow down. When I walk him, he carries dogfully on, hiding any discomfort from me. I'm learning to tell the difference.