I was on the bus earlier on and a lady got on with a medium size dog (not a guide dog), this is perfectly acceptable where I live.
She sat on a fold down seat at the front of the bus (the pushchair and wheelchair area). The woman sitting next to her (on the normal seats), so facing her rather than next to her iyswim? This lady had her daughter with her,she was under 5 (I think).
Anyway the little girl practically backflips on to my lap in her effort to get away from the dog. Repeatedly. She is obviously very frightened. Mum is obviously used to this and doesn't make a fuss,just goes about calming her down.
The woman with the dog says to the little girl "don't worry I won't let him bite you". Why on earth would you say that to anyone never mind an obviously frightened child?
There was nowhere for the mum and daughter to move not the woman and dog. So it couldn't be helped. But the woman kept going on and on about how she wouldn't let her dog bite the little girl. 
I have a dog, I like them. But I just thought what the woman was saying was ridiculously stupid. The dog was a placid old thing. She could have said "don't worry,he'll just sit quietly, he won't come close to you,I can see you don't like dogs".
I honestly wanted to bash my head about the window.