Aggressive dog on walk..

[Jan in CA]

Yesterday when DH and I were out walking our little dog, Foofoo, we encountered a very aggressive black lab. He ran up to us from a culdesac growling with hackles raised. I picked up Foofie and DH told me not to move. He kept telling the dog to go away and he took out his pocket knife because it was obvious from the way the dog was looking at me and Foofie and he made an attempt to go around DH to get us. He had on a collar with long, yellow nylon rope tied onto it that had the end frayed as if he'd chewed through it. The woman who owns him came running and got the dog finally, but it was pretty tense for a few minutes there. We didn't say anything and now I wish I had.

So my question.. is there something we can take with us on a walk to protect ourselves..or at least give us time to get away should something like this happen again? Bear spray comes to mind, but there may be something for dogs...? I'm afraid to go out for a walk with Foo now by myself.