I stumbled across this post while browsing for I can't remember what...But yes, that yogurt looks like sheep's milk to me, too. If you have not yet, you owe it to yourself to try bivolsko mlyako (water buffalo yogurt). Usually you can see hand written roadside placards advertising its availability in mountain villages. I had some in Bansko(?) in a restaurant with a "treehouse" seating area. It was served with wild mountain berries and although years have passed, I can still taste it. Go in the off season, though.