We have two gelded mini-donkeys....best part is we live "in town" (Denver). My neighbors don't know what to think!
Our boys ("The Boys") do very well with other animals. We actually rescued them because they were being neglected by their owner (real POS of a woman) and being abused by a young mule. Arlo is the younger of the two and he is terribly knock-kneed as a result of being dominance mounted by the mule at a very young age. It took us a few years to get him social and we still have a long ways to go.
However, one of our biggest tools in the battle have been other animals. We live in a really weird part of Denver that has many Ag zoned properties mixed in with apartments/townhomes/condos. Literally, the people across the street keep two
beef cows! Anyway, we've got goats, sheep, pigs, cows, horses, and a couple of other critters living within walking distance of our house...in town. The Boys keep many as friends. Their friends will come visit for a few hours and a few have even stayed for 'sleepovers'. The Boys are fiercely protective of their buddies, so long as their buddies are in the pasture. The Boys have many, many, many canine friends that visit daily, but their posture changes drastically if they have 'friends' visiting within the pasture.
Granted, our minis are sweet to a fault. They are just very accepting. But I'll echo the comment above about being careful to watch them around young, or very small animals. While 'playing', they will play like they're playing with another donkey. That generally involves kicking with their front legs. Arlo once knocked our bulldog's skull so hard that we heard it from the other end of the pasture. He was really sorry about it and slowly followed the bulldog as she stumbled over to us. He genuinely loved that dog (so did we), but he got excited playing and did some damage. Dog was fine until she got cancer, but that's another tale.
They are also keenly aware of domestic and not. The wife and I both
volunteer at a wolf sanctuary. Once when she came home (it's a three hour drive), she stripped down on the back porch to avoid bringing any bugs in with our house critters. The Boys and I happened to be in the backyard at the time. Both of The Boys ambled over to her pile of clothes and gave it a sniff. Immediately they began to stomp the pile of clothes, then ran like hell. We see the same behavior when we come across coyote scat on walks; very obvious aggressive posturing and behavior. But around domesticated dogs, they are wonderful and mostly gentle.
These are my first donkeys and I never in my life thought I would own donkeys. So my experiences are strictly limited to my Boys. They are naturally protective, but will not hesitate to attack something they don't think belongs. When I sleep out back in a hammock (I do a lot of winter testing with my hiking gear), they always come check on me after they hear the coyotes go by on one of their adventures. They seem to know what they're supposed to look out for and what is to be ignored or embraced. Really neat animals and I'm tickled I've gotten to
experience them.
I would have no hesitation about filling my pasture with sheep...with my Boys. They're just chill like that. YMMV.