I think how dogs get on with all animals depends on whether they've met that type of animal before, what kind of interraction they've had and also, what their personality is like...ie...if they spook easily.
Finn is wary of horses when comes across them suddenly on one of our walks when they canter past at their fast pace and it frightens him so he barks. When they are in a field just munching away, he doesn't even take any notice
Willow on the other hand has always reacted to them even chewing grass so I've worked recently with her feeding treats and her reactions have very much lessened to the extent that when a horse cantered by her the other day, she gave no reaction at all.....I'm sure if I could get Finn near a field with horses cantering I could give him the same positive feelings to busy horses.
Alfie doesn't give a hoot