When Rex, Boss, King, and Duke exit the trash compactor, they are shown to be covered in dirt and soot. However, when the shot changes to the point of view of the drone (looking down at the dogs), all four are completely clean.
Near the beginning of the film, a pack of white dogs walk up to a bag of garbage that was dumped in front of them before being confronted by Chief's pack. The film then cuts to a wide-shot of the packs snarling at each other from either side with the bag in the middle, even though it was right in front of the white-furred pack in the previous shot.
When visiting Jupiter and Oracle, Chief, Duke and Rex all stand closest to Jupiter with Boss and King standing just behind them. When Atari pulls out his picture of Spots, Boss and King are now standing next to Duke and Chief with Rex standing behind them.
In a lot of the scenes that feature simultaneous interpretation, the interpreter will begin to say something in English before it has been said in Japanese. In fact, because the verb comes at the end of a Japanese sentence, it is impossible to interpret in the manner depicted in the movie. Even the very best interpreters will be a few seconds behind the Japanese.
Many of the signs contain incorrect or awkward Japanese, as though produced by an advanced (but non-native) speaker.
Messenger owl drinks water. Owls do not drink water; the only fluid in their diet is the blood of their prey.