Slight Aggression towards other dogs - well socialized
I have an intact 12 month old male GSD. He has been in daycare since he was 3 months old and has been off leash before than as well. Daycare staff have made comments that Jaeger would never hurt a fly he is so sweet, gentle and submissive. He has never showed any aggression towards any human, cat or wild life.
Very recently we have noticed he has begun to snarl at other dogs off leash and on leash. His patience for playful dogs is rather limited. About 3 weeks ago he went after a lab puppy (who also was intact) nothing happened he listens well. So I was able to stop him and go.
Today however he was in daycare and bit a puppy that wouldn't leave him alone. The staff say that Jaeger gave several warnings to the puppy before the bite (not separating them is a different concern).
I would like to nip this aggression in the butt as he is a huge 75 lb dog (and growing) that can't afford to be aggressive.
I poke him in the ribs when I see him snarl at other dogs and say NO. I cant do anything with him at daycare.
Any tips that I can curb this behaviour for when I am present and when I am not (daycare)? I prefer doing the training at home instead of obedience but if I have to take him due to aggression I will.
Thank you all for your tips.