Hi, I live in the UK.
I have just got home from walking my 4 1/2 month old border collie puppy.
She normally has good recall but will suddenly chase after people in the park barking aggressively a just totally ignores me. It seems to be men walking on their own.
I have tried taking tasty treats to encourage her to come back to me, squeaky toys to distract her and playing with her to discourage her from doing this.
Today was the worst, she was very happily playing with 2 other border collies and then suddenly set off after a man who was just walking, she barked very aggressively and jumped up at him.
When I eventually got her back I carried her over to the man to apologize. I keep her on the lead for much of our walk due to this behaviour. Any advice would be very much appreciated.