When walking my dog, I use a 6 foot leather leash. I find that the leather leash gives me a lot more control because I can very quickly change leash length and tension. The closer I place my hand to the collar, the better control I have.

As for what is triggering the dog reactivity behavior, sometimes it can be difficult to tell. Our dogs can smell things that we cannot, and catch canine body language that may not be apparent to us. Controlled desensitization exercises with a variety of different dogs, helped my Shiba Inu become more relaxed during walks, and helped to raise his reactivity threshold. Getting another set of eyes, especially a professional set of eyes can also be helpful.

Im convinced its the scent of the dog that triggers him because the first time I saw him behave like this – the dog was not in his visual range – we had stepped in an elevator in my apt building -G was on the leash, and he got very agitated – as soon as the door opened, he bolted in the direction of the dog who by then was OUTSIDE the building and still not within visual range. Normally when elevator door opens Gordie waits for me exit first, and then looks at me for a decision as to which way we will leave the building. But this time he was on a mission and just bolted in the direction of the back door – finally making visual contact with the trigger dog where he went agitated to aggressive.

I am truly baffled as to understand what causes this aggression and why he reacts as he does. But when it happens I stay calm and try to create huge space between him and the trigger dog but its not easy.

Any thoughts?

My Shiba Inu, for example, would get reactive sometimes because he is over-excited and wants to meet other dogs. Holding him back with the leash would turn that excitement into frustration, and then he would redirect that frustration back onto the leash with biting and jumping.

Other times, he would get reactive because of what he *sees* as threatening gestures from other dogs. For example, he does not like strange dogs sniffing his butt. Here’s why.

Some dogs may also get protective over their people, protective over space, or protective over food and toys.

Some dogs may be fearful when new and strange dogs invade their space and force a greeting.

Dogs also pick up on the energy of the people around them. If the people around are fearful, stressed, or uncertain, our dog may pick up on that, and start to get stressed himself.

I try to set my dogs up for success and I pick the dogs and people that we meet very carefully. Sephy does not like dominant dogs, so we only stop to meet larger dogs that are relaxed and playful. I do not expect my dogs to be friendly with all the dogs that we see. Most of the time, we ignore other dogs, especially if we have not seen them before.
http://shibashake.com/dog/my-dog-is-friendly

Some things that helped me with Sephy in terms of reading his body language-
1. Spend a bunch of time observing him (some people will also record their dog and watch things back in slow motion).
2. Spend a bunch of time observing him interact with friendly dogs.
3. Reading books on dog body language. Turid Rugaas is probably most well known for her work in this area, but there are many other books.
On Talking Terms With Dogs: Calming Signals
4. Get private lessons from a good professional trainer. A trainer can meet with Sephy, observe his behavior and interactions with other dogs, give me pointers on how to read his body language, as well as provide suitable dogs for retraining.
5. We did a lot of dog-to-dog desensitization exercises with Sephy. These exercises are structured and safe, and they gave me many opportunities to observe Sephy while in the proximity of other dogs. It also helped Sephy to get more comfortable around other dogs, to stay more calm, and to use other behaviors for dealing with stressful encounters.

Hope this helps. Let us know how it goes.

The key with desensitization exercises is to start with a weakened version of the other-dog stimulus so that Sephy could still be in-control and could still learn from the experience. Once Sephy starts to react, it is too late and the best that I can do is remove him from the situation. Otherwise, he will just keep amping-up and start to associate those feelings and behaviors with other dogs.

My old house was in a more busy area, so initially we would drive Sephy to a quiet trail for our walks. We also took him to our local SPCA for desensitization sessions with the dogs there. We did the exercises with one of their trainers, and with different dogs that they picked based on Sephy’s temperament. We only did exercises with one dog at a time, but we would switch through 2-3 per session.

Given what you describe, it may be best to consult with a professional trainer, preferably one who has access to calm dogs that she can use to help with training.
http://www.apdt.com/petowners/choose/

I also do dog-to-dog desensitization exercises with my dog to help raise his reactivity threshold and to help him be more comfortable around other dogs.