What to do when you can't control the threshold?

I dislike halties in general. But this is the one place I think they have a good application. Sport used to do the same thing (scratch his face to get it off when other things were exciting him) But it was a very useful tool to get his focus back, in the same way a long line is an excellent tool when working on recalls. You can gently ensure compliance.

I don't like them for daily use.

With Nyx's reactivity a halti worsens it. It's fine if she chooses to look at me, but to force her head to turn away from the stimuli increases her anxiety. When she's able to see what she's worried about, she can think it through and sort it out and calm down. Just because her head is turned in my direction doesn't mean her thoughts are.

Thanks guys. Unfortunately in the city there are really no class settings in an area big enough where he wouldn't be only a few feet from other dogs.

I'm wondering how he would do if he was playing with another dog, calmly, and I clipped the leash on? Unfortunately, I don't really know anyone who has a dog we can have play dates with. A friend with a dog did just move nearby, but her girl is significantly smaller than Tom and a little bit dominant, too. We can use her for distance work (parallel walking and such) but I'm not really comfortable letting them play together.

Air horn. Let it be your best friend.

I had a dog that was absolutely crazy DA. He would yelp, yodel, bark and pull until his nails and pads were shredded all to get at another dog. No amount of me saying, "You want a cookie? Here's a yummy hotdog!" was going to make a difference. No yelling made a difference. So I had to think "What on earth is going to get this dog's attention so I can redirect him?" That's when I thought of a bike horn or those air horn thingies. I went with the air horn.

Let's just say that the first time he started acting a devil on a walk and I lifted the horn and pressed the button, he jumped and nearly left his fur behind. I was then able to keep his attention enough to redirect him onto me an the reward (hot dog) vs. the other dog.