There are plenty of people with dogs that seem quite balanced most of the time, but when they are put on a leash and taken for a walk show aggression towards other dogs and people.
I know Ed has to have covered this somewhere or in multiple places, but I'm just not sure where. Is this behaviour just pure aggression and is covered in the dominant/aggressive dogs video? It seems more complex if it's only ever during a walk on-leash, like the dog was somehow conditioned to react this way (inadvertently)

I know it's been addressed (somewhat) in a couple of the desensitizing threads.



(I'm sorry I don't have time right now to look ... )

There are a few different aspects of leash aggression;
a, Being on lead removes the 'flight' option from the dog.

b, Being close to the owner can either make the dog want to protect the owner - OR use the proximity of the owner as 'back-up'

c, The owner inadvertantly tenses up on the lead, which makes the dog anticipate a threat - 'if mum is scared then that dog must be really bad'

d, dogs can become frustrated on lead because they want to play but cannot, the more that they bark and lunge, the more they are held back increasing the frustration. Generally this looks aggressive but isn't - however it can turn into aggression.

e, dogs cannot properly meet & greet, or ignore and give a wide berth to strange dogs when they are on lead. Removing their natural behaviour, can lead them into making bad choices. We often force dogs to approach face to face (on sidewalks etc) and that can create / reinforce aggression.

There is more to it than that but that's all I can think of right now. It's 4am and I'm off to a long-overdue bed.