The specific term furry fandom was being used in fanzines as early as 1983, and had become the standard name for the genre by the mid-1990s, when it was defined as "the organized appreciation and dissemination of art and prose regarding 'Furries', or fictional mammalian anthropomorphic characters". However, fans consider the origins of furry fandom to be much earlier, with fictional works such as Kimba, the White Lion, released in 1965, Richard Adams' novel Watership Down, published in 1972 (and its 1978 film adaptation), as well as Disney's Robin Hood as oft-cited examples.

https://en.wikipedia.org/wiki/Furry_fandom

No idea why people would lose their minds about this either, though.