Icebergs can be misleading as most of their mass and size exist out of sight, below the surface. What may appear to be a small chunk of ice can actually be a very large and dangerous obstacle, the same comparison can be made for training a dog with reactivity issues.
Take a look at the picture above. You will notice some more obvious (above the surface) aspects of training and managing a reactive dog. Items such as timing, the ability to read your dog, get their attention, and proper education of how you want your dog to walk with you are all important. However, just like an iceberg, the bulk of reactivity issues are not caused by what’s happening on your walk; the build up is happening below the surface.
Even if you’re doing everything correctly with your dog while on a walk, your efforts will be for nothing if your dog spends the rest of their day outside of a calm state of mind. Some of the activity I am referring to could be fence fighting and window barking, reinforcing nervous or fearful behaviors, constantly running in and out of the dog door every time they hear a noise, living a life with no structure or boundaries, being left unattended in the yard, lacking well-rounded socialization, and so much more.
Leash reactivity can absolutely be managed and improved but it needs to be addressed as a whole package (above and below the surface).