Despite the title and the fact that it claims to be "based on the books The Howling I, II, and III by Gary Brandner", the film is actually unrelated to any of Brandner's novels other than being a story about werewolves.
This is one of two entries in the Howling franchise with no character seen in any other Howling film (Stirba, Werewolf Bitch served as a direct sequel to the first film, with Karen White reviving in her tomb, while 5, 6, and 7 all have Elisabeth She as Mary Lou and other common characters). An oblique reference to the previous two entries occurs when Barry Otto's character asks the Russian woman if other groups of werewolves live elsewhere, she says "Africa....China....maybe California". This may reference the varied groups of werewolves who attended to Stirba in Howling II, and Howling I and II took place in California. The other sequel to have this distinction is the 2011 reboot The Howling Reborn.
Hurlements III (1987) uses only two elements from the novel "The Howling III" by Gary Brandner, those are: the werewolves being portrayed in a more sympathetic light and humans as a danger to their existence, and the experiments being performed on the werewolves such as hypnosis and forcing a transformation against their will.
In Donny's bedroom a poster can be seen for Les entrailles de l'enfer (1982), also directed by Philippe Mora.