When Bojan was 10 years old, his father returned from war and with him he had a dog. This dog was a gift from his father in order for protection. In the beginning, Bojan was very excited for the sentry, because he had never had one before.
Unfortunately, Kaiser was not as he expected. It turns out that the sentry is very aggressive and dominant - even the neighbourhood was afraid of the dog:
“Kaiser had a bark you could hear all along the street, and made use of it often; so often, in fact, that the paperboy made his deliveries from across the road and the local children started taking the longer route to school.”(P. 2, L. 33).
The father’s dominance also really appears in the end where the father shoots Kaiser in front of Bojan:
“The blast went off right by his ear, and for a moment his heart felt punched, like someone had swung a hammer directly into his ribs, and the deafening contact of it went through him.
The mastiff folded up and fell. It looked almost asleep, lying there, the black face rumpled into the carpet and the stain, darker now, spreading around the big forepaws.” (P. 5, L. 32).
Bojan’s father found out that he had been torturing Kaiser. To teach him a lesson he therefore killed the dog in front of Bojan.
This symbolize that he believes that dominance and power is a good way to discipline his child. By torturing the dog by pretending to shoot, Bojan in somehow tried to achieve a form of power in relationship to both his father and Kaiser.