Old Joe the black cattle dog has known a better day
Around his jaws he is looking rather gray
He still works cattle but at a much slower pace
A young dog is being trained to take his place,
Old Joe a great cattle dog from a great working line
Is getting old for working cattle at nine
Though still keen to work nowadays he easily tire
The old legs tiring though he still has the desire
To work at cattle but his owner Jimmy say
That Joe is nearing his final working day
He will retire him he has done enough
At his age working cattle for him is too tough
He was a renowned working dog in his prime
But dog and master must bow to father time.

Francis Duggan

http://www.poemhunter.com/poem/old-joe-the-black-cattle-dog/