Due to the death of which animal did the main character of the film "John Wick" begin to take revenge?

"John Wick" is a 2014 American action thriller film directed by Chad Stahelski, in his directorial debut, and written by Derek Kolstad.

The story focuses on John Wick (Reeves) searching for the men who broke into his home, stole his vintage car and killed his puppy, which was a last gift to him from his recently deceased wife.

The film was met with positive reviews, with critics labeling it as one of Reeves' best performances and one of the best action films of 2014.

"John Wick" earned a mostly positive reception upon release, attaining praise for the action sequences, direction, visual style, pacing and the performances of the cast, especially Keanu Reeves as John Wick.

Peter Debruge of "Variety" spoke highly of the film, "Back in action-hero mode, Keanu Reeves joins forces with his Matrix stunt double to deliver a slick and satisfying revenge thriller."

Ealasaid Haas of "San Jose Mercury News" described John Wick as a "disappointingly standard revenge movie."