[Duncansmom]

The family's dog was bought for a guard, Chained to a post in a chilly backyard, Housed in a shed that was airless and dark, And every few weeks had a run in the park.
When bordom set in with no fun and no work, One day it broke loose and went quickly berserk, Pa could'nt fathom just why it went wild, as it flattened his wife and then bit his child.
The police were called in to sort out the mess, and the whole sorry tale was revealed by the press, The Rescue Society was really annoyed,
So, the dog was rehomed and the owners destroyed.

Author unknown

I think this sums it up pretty well.