* {{Blooper}}: When Tod is being chased by Chief a second time (as an adult), there are several shots where his collar is missing.
** During the first chase, Chief goes after Tod while dragging his doghouse barrel behind him. When Amos runs out after them in the next scene, however, there are still two barrels: one with Copper tied to it and an empty one that should still be attached to Chief.
** At the beginning of the film, just before we see Tod's mother, the camera zooms through a spider's web, however the shot is ''very'' blurry and out of focus. According to some of the animators who worked on the film, the camera operator for that scene was new and didn't know how to properly film the animation of the spider web before the shot of Tod and his mother.
* CreatorBacklash: Several notable animators, including [[Creator/{{Pixar}} John Lasseter]], Creator/DonBluth and Creator/TimBurton, rarely speak kindly of this film, citing it's tight-budgeted animation, which all but did away with the innovative technology the company had invented, as the final sign that Disney had become a [[{{Flanderization}} shell of it's former self]].
* KeepCirculatingTheTapes: It's pretty hard to come across a copy of the book. If you want to buy one be prepared to spare $200 to $300.
* HeyItsThatVoice: Tod is Mickey Rooney, Copper is Creator/KurtRussell, Amos Slade is [[Film/WillyWonkaAndTheChocolateFactory Grandpa Joe]] and [[Series/ChicoAndTheMan Ed Brown]], Vixey is [[TheSwanPrincess Queen Uberta]], Chief is [[Disney/RobinHood the Sheriff of Nottingham]] and [[Disney/TheAristocats Napoleon]], the grumpy badger is [[Disney/TheRescuers Rufus]], and Boomer and the porcupine are [[Disney/TheManyAdventuresOfWinnieThePooh Tigger and Piglet]], respectively.
** Young Copper is voiced by a young CoreyFeldman.
*** The semi-sequel has [[TheBackyardigans Austin]] as young Tod.
** In the Japanese dub:
*** Tod: Michihiro Ikemizu ([[{{Patlabor}} Isao Ohta]]) and in the semi-sequel, he's voiced by Reita Shiboi, who voiced ''Disney/{{Bambi}}'' in also their respective sequel.
*** Amos Slade: Creator/ChikaoOhtsuka ([[VideoGame/MetalGearSolid4GunsOfThePatriots Big Boss]], [[Franchise/SonicTheHedgehog Dr. Eggman]], and Goemon Ishikawa XIII in the first series of Anime/LupinIII.)
*** Chief: Osamu Saka ([[{{Patlabor}} Seitaro Sakaki]])
*** Dinky: Creator/YasuoYamada ([[Anime/{{LupinIII}} Lupin III]])
* LifeImitatesArt: Meet [[http://www.buzzfeed.com/summeranne/real-life-fox-and-the-hound-best-friends-will-melt-your-hear Sniffer the fox and Tinni the Hound]]
* RecursiveAdaptation: The Disney books were inspired by the movie, which was inspired by the original novel.
* TroubledProduction: There were many troubles going on with the production. Several veteran animators either retired or died early in production, batshes of animation drawings were stolen, leaving several scenes to be rotoscoped from pencil tests, and Don Bluth led an exodus of practically half the animation team, which delayed its release by six months.
* WhatCouldHaveBeen: Creator/DonBluth was assigned to co-direct the film until he and his colleagues departed from the studio in 1979. Scenes he worked on were the scenes of Widow Tweed milking the cow and her grabbing Slade's gun and accidentally shooting it.
** Originally, Chief was going to die, thus making Copper's revenge against Tod much more extreme, but the idea was discarded for being too dark and was rewritten so Chief would get injured instead.