Bryce L. Martin sent the inspiration for this short tale.
The story concerns a butcher who went into a petshop. It seems he fell in love with one the seabirds in the shop. Alas, he had no money to spend, but the shop owner agreed to give him the bird in exchange for some of that delicious German sausage. The deal was made.
It seems he took a tern for the wurst!!
A variant on this pun is in a Groucho Marx movie in which he said the patient took a turn for the nurse.