Shelter dog being scared/hates dogs ; what can I do to help him focus on US instead of things around

Hello everyone!

I posted a while ago about Bossa, a dog I was caring for in a shelter. He got adopted, but is back because he was too energic for the child of the family.

Since he came back, 2 - 3 months ago, I'm trying to work on his education ; alone , 1-2 hours a day. I'm not an expert at all so I'm here to seek your help !

To context a bit ; He's a young American Staff (2 yo). He had a poor early life. Got bouncd from family to family, got beaten and probably got attacked by dogs many times (he has white spot on his black coat like scars), we think that that is why he's so scared/hates so much dogs.
This is a dog that has a hell lot of energy, but he is super sweet with people he knows.
The problem about that, is that he barks a lot in his enclosure, which doesnt encourage people visiting to care about him. So I'm afraid he will stay here for a long time.

To try to fix this, we launched a little program for him and an othhr dog as a test ; program in which we will train him everyday (for the moment it is only sit/stay etc) and we added some toys for the concentrtion in hs enclosure (for exemple a Kong toy with food inside that has been put in the freeze so he takes a lot of time to eat it).

We're starting to see a little evolution inside the shelter/ he's more calm in his enclosure.

Here comes the problem : He's still going crazy everytime we cross an other dog on our walk. (He barks heavily, pull the leash extremely, etc)
I am the only one going on a walk with him every day (almost) for approx an hour.

For the moment the walk goes like this ; We leave the shelter and walk for about 20 minutes till we arrive to a countryside walk, where there is nothing around. The first 20 minutes he his still excited, isnt focus on the walk at all, he's just focus on the barkings he ears and the dogs he sees/saw. After that when we're on the countryside walk, he just becomes calm and more focus (not 100% focus)

What do I need? I need from you some ideas or procedures to do to make him focus on me whenever i need to. For exemple I do want him to focus on me when I say "here" when we cross a dog. All we want for him is him to feel better in his head and in general.
I know a shelter is not the place to do it, but we have to. We want him to feel better with other dogs around, listen better, help him focus on things, because he has an attention pan of a little kid.

We were wondering if we put a muzzle on him and if we do some exercices with him seeing other dogs from far away to close, It would maybe help him realizing every dog isnt that bad. If he could be more focus on his toys/bones/kong in the enlosure instead of the other dogs around/people passing by, it could be so helpful for him.


I don't know if it is clear, I'm sorry english isnt my mother tongue.


If you need to know more, feel free to ask.

I'm thanking you in advance,


Have a good one!