Dr Cazalet

In the short story The Under Dog, Dr Cazalet was a Harley Street doctor and acquaintance of Poirot. At Poirot's request, he put Lady Astwell into a state of hypnosis and asked her to recall the events on the night her husband Sir Reuben Astwell died.

According to the text, Dr Cazalet's clinic was located at 384 Harley Street.

Dr Cazalet is not featured in the film adaptation of the story in Series 5 of ITV's Agatha Christie's Poirot. There his role is undertaken by Miss Lemon who had taken up hynoptism as a hobby.