That's interesting XxemmafuriaxX that your mare actually calms down with all the popping out of the bushes. I suppose in her case it does occupy her mind trying to "find Waldo".
One of the last club trail rides (I was not on it), one of the members brought her dog. This dog supposedly is used to horses but was nipping at the heals of them. No correction by the owner. Finally her own horse went nuts and blew up. In turn, caused several horses nearby to get over excited (yes these were green to the trail horses, but have been doing nicely during the season). Caused quite a muddlefuddle!
Since I'm hoping to have Walka join the group next riding season (especially when T is out of commission due to her RU), I need to get him exposed to having dogs running by and near him. Ours has sadly passed a few years back (Walka loved to chase him, Bear didn't like that game), so I am thinking of borrowing one of my girlfriends wonderful golden retrievers and go for a little ride this spring. Of course I'll have her join me, since her dog will obey her and we'll keep the dog close by.
I do enjoy adding to the list of what can I expose Walka to now list. Fortunately, it never ends. But, he usually focuses on me and my reaction to things to determine if we should stand or run. Just another way to test our relationship.