Just recently there has been some more confusion about what breed(s) Frodo is or isn't. Most people see the markings and assume Rottweiler, but his build and demeanor seem completely different (plus he barks and Rotties are known for not barking at strangers). Anyway, I've decided to put together some pictures for comparison:
Frodo
Rottie
Black and Tan Coonhound (what the vet said Frodo is a mix of)
Australian Cattle Dog (what another vet said Frodo is)
Australian Sheperd
So what is he? Many breeds carry "the markings", but temperment and build are pretty strong indicators of breed as well. In terms of temperment, Frodo seems more like a poorly socialized lab.