Like most people, most canines have trauma on a scale of about 1-1000. Phycological trauma can be associated with physical trauma. For instance, a dog can be phytologically traumatized by being kicked or from being constantly yelled at, or even being in a home where everyone is constantly fighting with no physical contact with them. The brain drives the body. Anything in the environment that is present before, after or during the trauma can be associated with the trauma. These can be things the dog sees, smells, or hears. The way PTSD works is that the things associated with the trauma can cause the dog to relieve the trauma as if the trauma is actually occurring.
Dogs and people that have PTSD already live in a heightened state of arousal. Basically, like having your foot on the gas pedal standing still. This makes them appear jumpy because their reaction is always faster because they are ready for it.
Just like us, dogs are walking around responding to things based on things that have happened in the past. However, they cannot read this and understand that.
Healing comes when one person takes responsibility for the dog, identifies these triggers and instead of avoiding them, exposes them to those things in a controlled environment.
For example, if a dog is attacked by another dog, especially when they are young, they may be do reactive to any dog, or those that remind them of the dog that attacked them. If they were attacked by a several dogs, they may be OK with one strange dog, but not a pack.
With exposure we can show the dog that the triggers that they associate with the attack may be the same, but with redirection at the right time, show them that the outcome will not be the same. Without that redirection, the outcome plays in a loop in their brain.
When the dog is triggered, they automatically go into the fight/flight response. A part of that response in all mammals is a loss in the ability to salivate. If the dog is not salivating which aides in digestion, they biologically cannot accept food. Therefor using food to get a dog not to be scared of something does not work.
Dogs when confronted with a trigger usually respond on a wide scale of fight to flight. The goal when rehabilitating a dog or simply socializing one is that the dogs remain neutral when faced with the trigger. The more triggers and more triggers at one time presented and the dog can remain neutral, the calmer and more rounded the dog. A dog without a higher-ranking dog will always overreact one way or the other because they don’t have anyone else’s response to measure theirs against. So whether you are rehabbing a dog or socializing a pup, it is all about your reaction to the world.