To Chasing Shadows: Here's a link to an article on the animal porn film (I must warn you though, you may be offended by it)
Regarding 'Deep Throat' the film was banned for general release in Britain during the 70's but in some cases town councils allowed cinemas in their area to show a censored version of it. My friend saw the edited version of it in his local cinema. Later on, the BBFC passed the film uncut with an 'R18' rating, meaning it could only be shown or sold in specially licensed premises, and the edited version was released on video with an '18' rating. As I don't know which version of the film you've seen I don't really know what you consider tame. Also, bear in mind that Linda Lovelace claimed that she was forced to make the film against her wishes at gunpoint, and if this is so the film contains actual rape scenes.