Hi Tracy S,
This is exactly what happens with my doggies when I take multiple dogs for walk. All of my 3 dogs are rescue dogs and they are wonderful dogs. They all passed CGC test and know how to behave at home and at classes although each has different issues that we are continuously working on. Reacting to other dogs and cyclists is one of them.
Noah, our border collie mix, reacts so badly to cyclists, skateboaders and other dogs (big dogs only). Daisy becomes all excited when she sees other dogs. Holly has become very confident and she knows how to handle people and other dogs in a very mature way but she gets nuts when she sees squirrels on the walk.
I have been taking all different conbinations (2 dogs at a time) including our foster dog and I have noticed that if one of them feels even a slight uneasiness to a situation it spreads to the other dog and ends up a chaos!
I would suggest you take one dog at a time until they get used to the new walking course.
Border collies have strong instinct to react/chase something moving fast (bicycles, skateboards, joggers, etc.) but Noah is fine when I take him alone and have him sit next to me telling "Leave it" as a cyclist cruises by us.
Good luck and let us know how it goes
