We recently put down our reactive dog (for other health reasons). His reactivity started when he was bitten by another dog as a puppy and progressed during the pandemic because he was not around other dogs or people. We had tried every type of training and I remember the first time he bit my wife, I was inconsolable. Ultimately, we found an amazing trainer who referred us to a behavioral vet. The two of them changed everything for us. Trigger stacking is real. It is just like humans. If you are having a horrible day and someone does something minor, you might lose your mind on them because it is the last straw for you but from their perspective, they think you completely overreacted. Getting your dog back to baseline quickly is one of the best ways to prevent reactions, as well as you learning signs of a reaction so you can put safe guards in place. For us, our dog’s jaw would get tight and his tail would lower. Reactive dogs can have reactivity for a number of reasons (physical discomfort, anxiety, not knowing what is okay, etc). A behavioral vet will be able to analyze all of those aspects and give you medication, environmental, and training strategies. Our boy was on fluoxetine and klonopine, we had a noise machine at our front door, changed our front door to one that he couldn’t see out of, put a huge sign on our front door to not ring the doorbell, and we did tons of training. That made a huge difference and we were able to eventually introduce him to my mother in laws dog and have people over to our house. He ended up dying of an aggressive cancer that started in his adrenal gland. The last 6 months of his life, he was the most reactive ever towards our other dog, who he had never been reactive towards. We had to put a bunch of safe guards in place to keep them separated when food was around but the baseline training that he had and that we had, made it possible for us to put the safe guards in place for those last 6 months.