How is the dog when not on lead with strange humans? MY guess is you have not noticed any fearful or aggressive action when he is off leash. I am going to proceed on that basis but if that is not the case then a different apporach will be needed.Hobbes our 18 month old Dog when out walking on the leash on 3 occasions over a two week period has crossed in front of me to launch himself at a passerby when he does this he also growls and tries to snap
Keep in mind if the dog intent was to cause injury it would not be growling or even snaping these are all means for the dog to comunicate stay away
Actual this attitude is probably particially to blame for the dogs behavior. What you are dealing with is commonly caled on leash agression and the leash and the feed back the dog gest through the leash are contributing factors. Keepin in mind that a leash and or tie out is a contstraint on the dog normal ability to react to fearfull situation. It has no means of escape. So in the face of what it is scared of it resorts to it only alternative.i am worried as to his behaviour and need to stop this soon.
I thinkg the following articles will shed a lot of light on what is going onBeing on a lead makes your dog feel that it cannot escape. Dogs in this situation are more likely to be aggressive.
AGGRESSION: A Case History with Harry T
Help! My On-Leash Dog Barks and Lunges at Other Dogs!
keep in mind if it is dog or people the cause of the behavior and how to correct the behavior are not different.
Handling On-lead AggressionA high percentage of dogs tend to bark and/or lunge at other dogs while they are on leash. This is common for most dogs because they are very social animals and they want to approach and investigate other dogs. However, on a leash, they often do not have the freedom to approach and sniff. This can result in ON-LEASH FRUSTRATION, also known as BARRIER FRUSTRATION. Barrier frustration leads to excitement and agitation, which is displayed by barking, lunging, or growling.
Barking, Lunging, or growling is the canine equivalent of shouting, “AHHH! THIS LEASH IS SO TIGHT AND MY OWNER WON’T LET ME GO SEE MY DOGGY BUDDY!” Unfortunately, this reaction from a dog usually alarms his or her human companion, who may not let the dogs meet, and may become tense and angry at the dog. Dogs are very sensitive to their owner’s tension, frustration, and especially to any punishment they might receive from their owner. The dog then starts associating even the sight of other dogs with their human companion’s negative reactions, and eventually views other dogs as evil beings.
Nick Jones of Alpha Dog Behaviour discusses aggression when on the lead, and how to cope with it
FEISTY FIDO - HELP FOR THE LEASH REACTIVE DOG, 2ND EDITION
Keep in mind if you observe similar reaction or behaviors in situation in which the dog is not on a leash the the treatment needs to take a different approach.