They are pretty robust animals - seen a few hit by cars and they bounced off and carried on - just lucky you weren't a car then - the owner was lucky you weren't hurt.
Two incidents spring to mind with dogs - One... a large group of us were climbing Long Hill into Buxton, we were on the lower slopes coming out of Whaley Bridge, when a Jack Russel thing ran out at about 15 of us - bikes everywhere - was quite funny really as we all tried to either avoid the dog or getting bitten. Thank goodness there were no cars about, we were all over the place.
The other was climbing Birtles Hill near Monks Heath in Cheshire, a group of us neared the top when a large dog started chasing us along it's property, but we knew it was open at the end...... it was a case of fight or flight - one mate turned round, but I was too far so I pedaled...... I have never ever done
30 mph in a 42 x 19 before (or there abouts) and hope never have to do that again..... I still look out for the blasted thing even now (although though it's probably dead by now)...
Oh what fun ?