I have a 1.5 year old desexed male bordercollie and we have a daily dog group who meet after work and let our dogs play off leash at the local oval. My dog has been going since we was 14 weeks old so knows a lot of the local dogs. Recently we have had a huge increase of dogs including a lot of puppies ranging from 16 weeks to 11 months. Recently, my dog has shown aggressive behaviour towards the puppies who constantly lick his face and jump on him. He will tolerate the first few times but then all of a sudden he will snap and lunge and bite them. He hasn’t injured any but I am worried it might get worse. He doesn’t seem to have any patience with younger dogs of any breed and I want to correct it. Is my dog ok with telling the puppies to back off or should I be doing something to fix it? Any advice would help.