Good ol' Hewie is a dog we meet very early in the game. As early as the initial cutscene. When Fiona escapes from her cage, she is lingering around the room and senses something beneath a table. A large animal nestled in the shadows begins to growl and suddenly leaps out at Fiona! She falls on the ground while the white animal soars over her and disappears, escaping the room. She stands and finds a collar on the floow and realizes it was a dog.
"Hewie," she said, reading the name. Later, he is heard whimpering and whining having been caught, and tied to a tree outside of Fiona's temporary room. She heads out, steps down into the garden, and finds the injured Shepherd tied down with some wire. Fiona helps the dog who runs off, but not before looking back once, as if to say thanks. Or as if to say, I'm in your debt. Later, the Shepherd intervenes when Fiona is being attacked by the perverted Debitilas!
The rest of the game, Hewie is an intermittent companion. Fortunately, the game creates a lifelike dog in that he doesn't stay by your side like a magnet, and his legs don't move when yours do. He sniffs around, he wags his tail, he wanders off. The key to the game is to maintain a good relationship with the dog. Get him used to the sound of your voice. If you call him 3 times and he ignores you, scold him.
The reason this is so important is because throughout the game, you want him to follow you. If he gets left behind, you literally have to backtrack and find him. This can be very time-consuming. If you are attacked, you want him near and you want him to be a good dog and attack when you need him to. He will growl when there is a trap or stalker approaching. He will sniff around if there is an item or secret place nearby. Pay attention to him!