Yup, infruriating.
Trouble is out of control dogs, those that escape are invariably owned by people who probably shouldn't have any kind of dog, or even a hamster or gold fish.
The type of dog too seems to be an attraction to the wrong people.
Our trainer told us in this situation it's a good idea to make yourself as big as possible and yell at the top of your voice at the errant dog approaching you.
His theory is that the dog whilst aggresive, not under control will due to it's most likely home environment be scared of it's owner, so wary of any angry 'aggressive' behaviour from a human.
This struck a chord with us, as my better other half was walking our old dog Kipper once, when an escaped agressive German Shepard guard dog ran towards her and Kipper in the street.
'Mom' reacted by raising her arm and screaming 'F*"@K OFF' !
The dog stopped in it's tracks turned round and went back into the yard it was meant to be guarding.
Recently terrible news from Brighton a town on the south coast.
Two escaped Bullies attacked a Cokapoo, and it's owner - horrific injuries sustained.
And in South London a dog walker - walking six dogs I think - was attacked by the very dogs she was walking, and killed.
There is an increase here of serious dog attacks.
Again, the rise of a certain fashion breed - the Bully, is a factor.
But of course any dog can 'turn'.
I must admit I purchased a walking stick with a pointy end when Pop's was a puppy in order to defend ourselves, and also because the puppy theft thing was rife at the time.
Truth is I have never actually taken it with me though - yet.
Mind you one of the most worrying events was when Poppy was in her very first season.
An absolutely huge Doberman, who we knew, who Poppy had attempted to play with as a tiny puppy, soon learning that was a bit risky - not because he was a 'dangerous' dog. in fact he is actually ok - just too big - but he was a youngster too, and very interested in Poppy when she went into heat.
One day we were in the park, poppy on the lead because of her condition, when this dog turned up.
Firstly no owner in sight, secondly he had no collar on.
He wanted Poppy.
I had no choice but to lift her by the lead, in effect 'hanging ' her for a second, hold her to my chest and turn round.
'Mum' trying to grab him by the scruff of the neck as there was no collar !!
Next thing I had muddy paws on my shoulders as he decided I was the next best option to Poppy ....

Nightmare.
The owner came running, collar in hand, got hold of his dog.
Aplogising like mad, and said they were 'miles' away other side of the park, when obviously the dog got whiff of Poppy, slipped his collar and raced off.
Poppy isn't scared of this dog now, but if he comes over to say hello after a bit she gives him a little 'snap' bares her teeth and he listens and leaves her alone.