That scares me to death as well. That any dog sweet or agressive might come towards me and my dog.

What i would do, is try to carry with you at least one treat everytime you take a walk that way if some dog comes towards you, you might be able to calm her/him down by giving the dog the treat. One thing you must always remember DONT run because that will make them chase you even more. I would also scream at the dog/'s as loud as i could to get them to run away.

The advantage of having small dogs like me is picking the dog up, and yet if the dog is bigger than yours she/he can jump at you to get to your dog and probably endup injuring you.

I am sure that the dogs slip of something, i dont think the owner would allow them to roam free, especially if the owner knew her dogs would not get along with other dogs. Some dogs love people, but when they get with other dogs you dont even know who they are anymore, they go nuts.