Brian worked as a student vet employed by his brother, until graduating from the Royal (Dick) Veterinary College in Edinburgh in 1943, subsequently joining the Royal Army Veterinary Corps in India. On demobilisation, he joined the Ministry of Agriculture's Sterility Advisory unit, rising to become head of the Veterinary Investigation Centre in Leeds.
He was the model for the character 'Tristan Farnon' in Wight's semi-autobiographical novels, which were later adapted to the big screen in two films, and television under the name All Creatures Great and Small. The fictional Tristan was portrayed as a charming rogue who was still studying veterinary medicine in the early books, constantly having to re-take examinations because of his lack of application, often to be found in the pub, and subject to tirades from his bombastic elder brother Siegfried.
Unlike his elder brother Donald, who for some time saw the books as a great trial of his friendship with Wight, Brian made no objections to Wight's ne'er-do-well portrayal of him, and in fact seemed rather to enjoy the celebrity, appearing on television and lecturing at veterinary schools all over the UK and elsewhere.
He married Sheila Rose Seaton in 1944, and they had three daughters.