I've had a few dogs on leads bark or jump towards me when cycling but as I always slow down when going past dogs it's never caused a problem. First time a dog chased me was just a few days ago, I just slowed down almost to a stop and watched it running towards me, when it saw it had nothing to chase after, it just turned and wandered away. The best thing to do is just stop, if you feel the need, get off the bike and put it between you and the dog, but their instinct is to chase, so if you just stop moving, that usually is enough.
Since taking ownership of a black lab in the past year we've managed to get him behaving quite well, but the one thing we can't seem to stop him doing is barking at people going past on motorbikes/scooters. He used to bark at cyclists too but (touch wood) we seem to have got that sorted, it's the noise of motorbikes in particular that seems to attract his attention.