Though pork patties are pretty much unheard of at McDonald’s back home, they actually pop up on several international menus (most notably in Germany, where the McRib is a permanent item on the menu).
Though I don’t think you need much more than a day or two in Zadar (I was actually planning on spending a few days here, and then cut that down to one when I realized how small the city centre was), it’s definitely worth checking out. Maybe as a day trip from nearby Split?