Noel treats a seven-month-old fox red Labrador puppy with lameness, caused by a joint defect called osteochondritis dissecans. He explains that medicine can be given, but in the end the dog may end up requiring a complete ankle replacement or a joint fusion on both sides. Jo has travelled 400 miles to bring her beloved four-year-old springer spaniel Sophie to see Noel. Sophie's kneecap keeps slipping in and out of her knee joint, and despite several previous procedures, the problems persist. After an examination by Noel, Jo faces the further worry of osteoarthritis.