The park where I take my dogs attracts a fair number of rude dogs, the majority appear to be pale coloured lurchers & golden 'doodles - their owners are usually off somewhere in a world of their own, while their dogs are charging around, barging into other dogs, & causing all kinds of havoc. Consequently, Roly now has real issues with any dog that vaguely looks like a lurcher or a 'doodle, & tells them off before they do anything - if I see one about, I have to get him back on his lead before we get up close, otherwise, if he tells them off, the others think it's done something wrong, & then they all chase it off!!
There was one particular incident a couple of years ago, when my 3 were sniffing in the trees & grass, when this hugely overweight lump of a chocolate labrador hurtled towards them, barged into them, jumped about all over the place, & generally wound them up - there were the customary grumbles, then snarles & lip curling, non of which seemed to have any effect on the 'thug' , so they all had enough, & amidst much barking & growling, chased it off in the direction of it's owner, who naturally, was at quite a way off across the park!! She didn't take well to the dogs chasing her prescious, & bellowed, 'do you want to get your dogs on a lead - you need to control them!!' ... I pointed out to her that they wouldn't behave like that if her dog was better mannered, & didn't jump all over them ... her response was 'he's only a baby, he just wants to play, & your dogs are being horrible' ... & again I pointed out that they are entitled to react like that, if they're being jumped all over by a dog that must be as big as the three of them put together ... again, 'he's only a baby, he's only 10 months old' ... & after several more attempts to point out her dog's behaviour was unacceptable, & she deciding my dogs were viscious, I lost my rag & the parting comment was along the lines that how were my dogs to know he was a puppy anyway, as it's so overweight - & that she was going to kill her dog by over feeding it!!

....... ok, so maybe I shouldn't have said it, but she was really getting on my nerves by then, & it got rid of her, as she stomped off with her dog. .... have never seen it since, so maybe others have had 'words' with her over it's behaviour!!!