Herriot's real name was James Alfred Wight. The Royal College of Veterinary Surgeons' rules ban advertising, so he took his pseudonym from the Birmingham City football club goalkeeper in the 1952 Cup Final.
Although born in Sunderland, Herriot spent the first twenty-three years of his life in Glasgow, and never lost the accent, as can be heard in television interviews. Simon Ward however, plays him as a Londoner.
In the book, Herriot (Simon Ward) is vindicated by the autopsy on the cow's heart, but Cranford (Freddie Jones) complains that Herriot doesn't know the technical term for the congestion, and still doesn't know what he's doing.