My initial film idea is:

A man walking down the street,a bit down on his luck, sees an extremely cute puppy in a pet shop window. He buys it because he thinks it is adorable, not knowing the implication of his purchase, and takes it home.

We see an extremely tidy and clean house. The man takes the dog into his house and leaves it in his living room while he fetches it a bowl of water. He comes back and the dog has chewed up the mans slippers. The man gets angry and upsets the dog, the dog then wets itself which inturn makes the man angrier. The man then has an idea to build the dog a dog house.

(Montage style) We see the man contsructing all the elements of the dog house in his garden. When finished the dog house looks really bad and unsafe. He tells the dog to go in but the dog does't want to. The man forces the dog into the dog house. The man goes back inside looking very proud of himself and leaves the dog in the dog house.

The man closes the door behind him to notice some paw prints leading from the kitchen into the living room. He sees the dog rolling around on his furniture, getting mud and hair everywhere. The man flips in anger and grabs the dog by the scruff of the neck. He throws it back outside into the dog house and stomps back inside slamming the door behind him.

He goes to the sink to clean up, turning the tap on. waiting for the sink to fill he hears a little bark behind him. The dog is sitting behind him wagging his tail. The man finally snaps and chases the dog to try and get it out. The dog thinks its a game and continues to run. The chase lasts a few minutes (seconds in screen time) and he finally catches the dog.
The dog realises its not a game and wets itself again. The man then realises he left the tap on. he drops the dog and goes to the kitchen. The door is bulging under the water pressure. The door then explodes taking the man with it.

The man is dizzy. He looks up shocked and bemused to see his wrecked living room and the dog standing in the door way. A crack then forms up the wall. The house caves in on top of the dog.
The man looks shocked then sad.
He goes to the pile of rubble and starts to cry, realising what hes lost. He sees the dog house through the kitchen and walks over to it. He crawls inside and sobs.
After a while we hear another bark and the dog has re-appeared unharmed. The man smiles and the dog runs and licks his face. The end.