Have you ever been attacked by a dog and able to get it away..did you use pepperspray?

My baby is almots 2 yrs old, and we go for walks pretty often, and am wondering if I should carry pepperspray in case of a dog attack, not too long ago there was a loose pitt bull. I dont have pepper spray so I am carrying a kitchen knife in her stroller but I think thats a little much...any suggestions? Only serious answers please, I am very concerned for the safety of my baby but I am not driving right now.