Dough is a common way to misspell the proper name Doug. There are two very frequent occasions that you will find this form of misspelling.
1. Hispanic population – especially when ordering late night fast food at Whataburger and they have to ask you for your name to call your order when it is ready.
2. A typo on the keyboard because the letter h is right next to g so people type the word Doug, but accidentally add the h at the end. Spell check cannot pick this up because dough is still a word.
When I get my food at Whataburger and look at the order bag, it almost always says Dough.