There are guys who get some nice treedogs out of shepherd dogs. I have heard of using border collies and aussies as squirrel dogs. I believe some of the shepherd dogs are split off breeds from a breed called a treeing farm shepherd. These are old farm dogs that tree well. Also, Mountain Curs and Blackmouth curs are all-purpose dogs. They will tree, bay, and some guys use them for cattle. I have one and should be getting number 2 this weekend.