The Royal College of Veterinary Surgeons specifies what further training, exams and qualifications a veterinary surgeon must have to call themselves a Specialist in a certain subject.
To become a Specialist, a vet has to train and study, usually for 3-5 years, directly under other Specialists, focussing 100% of their time on their area of expertise. This period is usually called a Residency. After that they have to fulfil certain criteria to be able to take the Specialist’ examination. Once they have passed these examinations they can call themselves Diplomates in their Speciality and they can apply to the Royal College of Veterinary Surgeons to be registered as a RCVS recognised Specialist in their field.
To maintain their status as a Specialist they need to resubmit their credentials every 5 years to show that they are still active in their field of expertise.