Written under the expectation that the series was about to be canceled. With that in mind, Glen Morgan and James Wong were determined to go out on a bleak, nihilistic tone.
Inspired by an outbreak of bovine spongiform encephalopathy that had recently taken place in the UK - or mad cow disease as it was better known.
Bill Dow (Dr. Schroeder) later appeared in an episode of Stargate SG-1 (1997) with the same title: The Fourth Horseman: Part 1 (2005). Both episodes involve the outbreak of a terrible disease.