There is a very fine line between desensitising and sensitising - that's maybe what had happened here.
Sensitisation is when the stimulus (in this case, exposure to other dogs) is repeated, but to the point of annoyance. Like a colleague who has a habit of clicking a pen - most days you can tolerate it or ignore it, but one day, maybe in an important meeting where everyone is pressured and maybe you have other stresses going on, you haven't slept and you have a headache, and he is click - click - clicking. You have had enough, so you lose it and take the pen from him and snap it.
That's likely where your dog is at.
needs constant socialization with other dogs.
He probably doesn't. Or even didn't. Most of us try to aim for our dogs to be dog neutral. They are aware of other dogs, but neither magnetised to them, or reacting. We are their main centre of focus, and that makes training and so on all easier too.
I feel like the more socialization I give him the more he declines in his training and his abilities to even just walk by someone.
This just reinforces what I think.
I suspect what he needs is space away from other dogs. By putting on a big display, your dog is trying to frighten off the other dog, his body language is saying 'I'm loud and big and scary, don't come close to me if you know what's good for you'. And almost always the other dog will retreat, or be taken away by his owner, so your dog's behaviour becomes reinforced. It worked, so he knows he can do it again.
This sort of behaviour often happens when your dog is on lead, which means that he has found himself closer to the other dog than he would have chosen if he had been able to.
He will have an invisible radius of space around him where he feels secure. It's called flight distance, anything within that space triggers his fight or flight stress response, which you may have heard of. Find out what that is and keep him far enough away from other dogs that he is aware of them, but relaxed. That means avoiding dog parks - for him, they are like a busy, noisy, drunken party for a teetotal introvert with a morbid phobia of Covid. Your goal is to train that he doesn't need to react; not to stop a reaction in progress.
Reward him for being calm with something fabulous, like frankfurter sausage or a very special toy. The aim of this is to change your dog’s emotional response to the stressful thing (the other dog) by repeatedly pairing it with something good. In time, your dog will learn that scary dogs mean sausages appear and this creates something called a positive conditioned emotional response (+CER).
This website explains it in more detail -
Care for Reactive Dogs
Gradually, over weeks and months rather than days, you can work on reducing the distance. This may mean you have to be selective where you walk - choose places with good visibility so you can give other dogs a wide berth, or where you can turn and walk away easily. But - be aware that if your dog has had a stressful episode the stress hormone cortisol can stay in the body for some time. Studies in dogs are inconclusive but it may be several days. That means that if his cortisol is already high, the distance he was comfortable with on one day might be too close on another day. So the safe distance can change, watch his body language.
Alongside that you could train a 'watch me'. As your dog looks at you, mark and reward the behaviour. Ask for longer periods of watching. Then if a dog approaches, after you have worked on the distance issue, you can get your dog to focus on you and not the other dog. BUT - some dogs find this scary as they cannot see the thing they are anxious about so you need to judge your dog. And importantly, don't ask your dog to watch you if it is the other dog that is reactive. Your dog should never be in a situation where he could be at risk while he is complying with something you have asked him to do.
Trainers describe behaviour like this with reference to the three Ds. Distance, as above but also be aware of Duration - your dog might be tolerant for 10 seconds, but not 15; and Distraction - how distracting the stimulus is, a calm dog might not trigger any reaction at a given distance but a bouncy one might.
In addition, the conformation (shape) or even colour of some dogs can trigger a reaction. Very broad fronted dogs (such as mastiffs or bulldogs) create the impression of 'facing up' just because of their shape, which can be intimidating even if their temperament is perfect. And black dogs are thought to have facial body language that is harder to read. Some dogs will be more reactive to un-neutered males, or particular breeds for no apparent reason.
Learn what triggers reactions in your dog so that you can give him the extra support he needs.
