Todd's only companion, in his self-imposed exile, is Indy, his gorgeous Nova Scotia Duck Tolling Retriever.
Of course, Good Boy being a horror movie, the house turns out to be haunted but it is Indy who picks up on this first - sensing "something" in the shadows, a menacing black figure.
Meeting his grandfather's neighbour, Richard (Stuart Rudin), Todd is told that since the grandfather's death his loyal Golden Retriever, Bandit, has gone missing.
But Indy has been seeing Bandit around the house!
As Todd's health worsens, he becomes more aggressive towards his sister (on the phone) and Indy, with the poor dog eventually being chained up in the garden after he stumble's into one of Richard's fox traps in the woods.
But when Indy realises the ghostly creature has returned and Todd is in a very weakened state, the heroic dog breaks out of its confinement and charges back into the house to try and rescue his master.
Good Boy, the feature-length directorial debut of Ben Leonberg (who also co-wrote the script) attracted a lot of buzz when it was released last year as it takes the innovative step of showing this ghost story from its canine hero's point of view.
But, honestly, beyond that the film is a bit of a mess.
For some reason, Leonberg took a play out of Skinamarink's book and doesn't show any human faces (except the grandfather on old video tapes), which is okay as a gimmick, I guess, but just doesn't feel true to its core gimmick of having Indy as its protagonist.
Dog's love looking at human faces, because that's an important part of the bonding process between man and beast.
And then, suddenly, as the story lurches into its third act, we start seeing Todd's face anyway!
This inconsistency is emblematic of the confusing nature of the story.
The pacing of Good Boy is all over the place, repetitive and unnecessarily obtuse.
Matters certainly aren't helped by introducing Indy's dreams and visions into the narrative flow as well.
Yet, while the audience has to focus on every little detail of the story, due to the minimal dialogue and sparse non-diegetic score, it feels as though there's no reward, no explanations.
I'm not even sure if the "ghost" - which reminded me of the Rubber Man from American Horror Story - had a reason for doing what it was doing, what its apparent grudge with Todd's family was.
And while Indy was main character of the piece, it was very difficult to have any sympathy for his owner, Todd, despite the young man's chronic illness.
He's just wholly unlikeable, and you can't help feeling he was probably this unpleasant before he fell ill.
When we first meet him he's being obnoxious to Vera, and this attitude continues throughout the 72-minute movie. Sure, he has moments of fun with Indy, but these are few and far between.
Yet, Indy loves him and will do anything to protect him. Perhaps that's the point?
Again, I have to stress the idea of telling a haunted house story from the point of view of a dog is an incredible idea - we've all seen dogs staring at things in our houses that we can't see!
But, it feels that was all Good Boy has to offer: a clever idea wrapped up in a very underwhelming story.
Award-winning Indy is brilliant though and I hope he has a long and successful career in film and television (he was, for instance, the emotional support dog on the set of Daredevil: Born Again last year).
