From the other side of the fence:
Our jack russell terrier does not like other small to medium sized dogs and will growl and bare her teeth if they come too close. Bigger dogs she is submissive. She is a rescue dog and may have been attacked in the past.
When ever we see another dog we put her on a lead or pick her up. Despite telling other owners to keep their dogs away, or on a lead when they say hello, some people refuse to control their dogs.
Car: 2010 Jaguar XFR (Cat-back exhaust)
Gone but not forgotten: Highly Modified E90 335i LCI M Sport Manual (circa 480BHP/500lb ft)