As others have done, I wish to add my sympathies and wishes for a speedy recovery to the gentleman who was injured while riding his bicycle and attacked by a dog.
The issue raised, however, is equally a real concern to dog walkers. Unfortunately, it is a fact that most dogs hate turning wheels. It is also a fact that most turning wheels on bicycles make no noise.
Please, dear cyclists, warn us when you are approaching from the rear. Ring your bell, say hello, whistle — do anything to let us know a silent, spinning wheel is approaching. We dread this encounter as much as you. We will gladly tighten the leash or even pick the creature up to avoid a needless confrontation.
Many thanks. May we both have happy experiences sharing the beauties and benefits of this lovely community.