Distance and threshold
Reactivity
Reactivity is a distance problem before it is an obedience problem. If the dog cannot eat, you are too close.
Reactivity — lunging, barking, screaming on the lead at dogs, people, bikes, or vans — is usually a cocktail of distance, history, and handler mechanics. It is not a breed sentence and it is not fixed by a louder sit.
The working rule is threshold: find the distance at which the dog can still look, breathe, and eat, and train there. Flooding (walking into the crowd “so they get used to it”) is how you buy a worse week. Management — route choice, visual barriers, a feedable harness setup — is not cheating. It is the condition that lets a protocol exist.
Full spoke articles for street work, window barking, and fence running are in the queue. Until they publish, use the puppy socialisation map so you are not accidentally rehearsing panic in week twelve, and read editorial policy for how this publication treats behavior modification claims.
If a dog is injuring people or dogs, skip the internet. Manage, and see a qualified professional. Nothing on Dogmindlab is a diagnosis, a guarantee, or a substitute for in-person help.