For as popular as the franchise is very few ever seems to remember that the reason John Wick does what he does in the first film is because Theon and his idiot gang kill the dog.

Steal the car? Sure, annoying as fuck.

Beat him up? Definitely leaves some marks.

But Daisy, the dog/puppy, was a post-mortem gift from Wick's recently deceased wife as a way to try and help him move on from her death which both knew was coming.