The oral tradition has been at work again.

I've just checked the above version against the Harding broadside in the Bodleian which, dated at 1797-1807, is by far the oldest of the broadsides.

You can see the differences below (highlighted in bold print):

DOCTOR MACK

Now Doctor Mack no more employs
  The burden of my song, sir,
I'll [tell] you the life the priest enjoys
  And his constitution strong, sir.
He laughs and winks at those who drinks.
  To them he is not bound, sir.
He'll take a glass and let it pass
  And tally ho the hounds, sir.

CHORUS: Tally ho, tally ho, tally ho the hounds, sir,
He'll take a glass and let it pass
And tally ho the hounds, sir.

It is every day he can afford
  To dine on boil'd and roast, sir,
And then as great as any lord,
  He'll drink his favourite toast, sir.
It's his delight to drink all night
  His care in wine to drown, sir,
And in the morn he'll join the horn
  And tally ho the hounds, sir.—Tally ho, &c.

Now every day he goes to pray,
  The priest puts on his boots, sir,
And if the fox should pass that way,
  He'll follow in pursuit, sir.
So swift o'er hedge and ditch he leaps,
  To them he's not fast bound, sir,
And if he can he'll lead the van
  And tally ho the hounds, sir.—Tally ho, &c.

It happened on St. Stephen's day,
  The priest was gone to prayers [mass?], sir.
He heard the music of the horn.
  He saw bold rennard pass, sir.
He shut his book, the flock forsook,
  He threw aside his gown, sir,
Mounted his horse to hunt the fox,
  And tally ho the hounds, sir.—Tally ho, &c.

Once he had a pair to wed.
  The fox came in full view, sir.
The surplice he threw o'er his head.
  He bid the pair adieu, sir.
They both did pray that he would stay
  For they were not fast bound, sir.
He said that night to bed they might
  And tally ho the hounds, sir.—Tally ho, &c.

So never think this priest did wrong.
  He ne'er did fraud or harm, sir.
His life is worthy of my song.
  He has an honest heart, sir.
He ne'er opprest nor poor distrest,
  Which adds fame to his renown, sir,
But he thought no crime at any time
  To tally ho the hounds, sir.—Tally ho, &c.

Formatting tweaked a bit; punctuation added. –JoeClone 09-Oct-2008.