The family's PON was used to 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 boredom set in with no fun and no work,
One day it broke loose and went quietly berserk.

 

Pa couldn't fathom just why it went wild,
As it flattened his wife and then bit his child.
The police were called in to deal with the mess,
And the whole sorry tale was revealed by the press,
The Rescue society was really annoyed,
So, the PON was re-homed; and the owners destroyed.