Born in Wandsworth in 1945, John was educated at Emanuel School and the Royal Veterinary College, London, qualifying as a vet in 1969. Apart from 3 years in pharmaceutical research with Eli Lilly, he spent the majority of his career in general practice in South Wales, Essex and 25 years running a large veterinary hospital and mixed practice in East Grinstead.

John has worked for the BBC on undercover investigations involving animals on the Inside Out programme and for 10 years was a trustee of Animal Care in Egypt, an equine charity working in Luxor. Since 2010, John has been head livestock vet for the South of England Show Society. He is married to Joanna and has 4 adult children and 6 grandchildren and lives in Chiddingstone, Kent. They have a small herd of Sussex cattle.