When I first got Keeta, she was very afraid of strollers and bicycles. Her response at the time was to run away and hide. In a fear response, don't make a bid deal out of it. Be solid and grounded (your dog will read your energy), and act like the stroller is the most boring thing in the world, and being afraid is ridiculous. Icontinued taking Keeta out for socialization to places where there where people with strollers (parks, big-box store entrance areas, etc ), and she quickly lost her fears. The more I socialized her, the quicker she lost her fear response to novel objects, and soon only showed interest and curiosity, instead of fear and avoidance, to anything new.
Sarge will need more exposure to strollers and things being pushed around. Be ready to redirect his attention to obedience exercises and other things he can do *instead* of acting defensive.
With Keeta, at one point, she realized that strollers normaly held little kids as cargo - well, she just LOVES kids, and after that, if she saw a stroller, instead of trying to run away, she was pulling towards it, tail wagging in excitement!
BH, OB1, TR1, AD
Rottweiler/Hairy Dog mix?? Shelter rescue
Gryffon Vom Wildhaus