Marty was attacked by three big (HUGE) dogs once that were off-leash. Like you, I was just taking him out for a walk. One of the dogs picked him up in his mouth and scared me to death! It happened so quickly I didn't know what to do. I yelled at him and pulled on Marty's leash and he dropped him. I couldn't stop shaking the rest of the night. I just kept holding him and telling him how much I loved him over and over. Oh, and wanna know the best part? The owner looked at me, said "sorry" and walked away, leaving the three dogs to do what they wanted!
Marty was only about 6 months at the time. Thank goodness he was safe. We moved as soon as possible after that and haven't had any problems at our new house.