Noel diagnoses the joint condition osteochondritis dissecans in a hyperactive ridgeback named Loki, and discusses treatment options with his owners. Newfoundland Hugo is referred for his hip dysplasia, but Noel discovers issues with his elbow and knee joints, while Carol and Nigel bring their mischievous seven-month-old Havana kitten Zahra following a mysterious accident at home, which resulted in a broken leg.