Dog food!

Two immigrants from Africa arrive in the United States and are discussing the difference between their country and the U.S. 

One of them mentions he has heard that people in the U.S. eat dogs, and if they're going to fit in, they better eat dogs as well. 

So they head to the nearest hot dog stand and order two 'dogs.' 

The first guy unwraps his, looks at it, and nervously looks at his friend. 
"Which part did you get?"