I like this puzzle a lot, though my late night attempts failed to solve it. I spent several hours on it and enjoyed it even though I had no success. My mistake was that I kept on being tempted to continue the loop with my hunches, rather than search for more separate areas that I know something about. Hunches are dangerous for large puzzles.
This was probably the most difficult puzzle here that I managed to do without guessing. At first I had absolutely no idea how to begin thanks to the novelty of sheep and wolves addition but it somehow started to flow naturally. Halfway through I realized I'm not building a loop like I always did - I'm building a maze with no exits for the poor sheep... Yea, I'm weird.
Great job Maarten! It took me a few hours but I enjoyed every second of it!