High pitched barking on leash at some dogs

[Eas2]

Shadow is almost 2 years old, we rescued him when he was about 4 months old. He’s really good in most situations & did well in his 2 basic puppy classes. He’s at the end of his 4th agility class.

We have 3 other dogs, 2 Irish Wolfhounds age 2 1.2 & 4 yrs, a terrier mix age 12yrs.

In the agility class there is a PWD that Shadow has taken a dislike to, he bares his teeth at this dog if it looks our way or comes close...he’s never done this before. This morning at the beginning of our usual morning walk, 2 huskies were behind us with their owner. Our other 3 dogs were off leash & ran back to greet the huskies, Shadow shrieked so loudly & stood on his hind legs in an effort to get free. We’ve not experienced him doing anything like these two scenarios before. He has always played well with every dog he’s met.

Any ideas of why he’s changing? & any ideas on how to resolve 

Many thanks in advance

[CptJack]

He's doing this because he's a 2 year old Border Collie and he's becoming socially mature and less tolerant of other dogs.  That's normal - or within the realm of normal.  You may also be dealing with some frustration stuff re: the leash,   but most fully mature BC (and indeed herding breeds) grow out of 'playing with strange dogs' or being good/loving every dog they meet.

 

Work on focus on you and work with you in the presence of other dogs. 

Don't try to make him 'friendly' with them.  That will back fire. 

[Eas2]

Thanks for your advice Cpt Jack, I did try a ‘look at me’ with a treat in hand, but I think he was too hysterical to hear me...I will try to get his attention earlier in future