Hank is a service dog who detects her seizures. Unfortunately 3-year-old Hank can’t walk for reasons that might be apparent.
Because he is a service dog, by law he can ride in any cabin on the airplane, no matter how large he is. If the dog can’t fit under the seat or on the passenger’s lap, both may be moved to the bulkhead row. The passenger also has the option of purchasing a ticket.
In this case the passenger purchased a second first-class seat for Hank.