I did this when I had a paper route.
Take 12 or so Strike Anywhere Kitchen Matches. Put a rubber band around them. Keep to or three bundles under your seat.
Strike and throw at the dog when he is very near.
A hit on his nose will end his chasing career.
It worked on a Large Fast German Shepard that tried to bite me.
He got it right on the nose.
Never saw the dog again.