Eye contact with a dog is considered a challenge (aggression). Don't make eye contact with him. Put your hand out to him palm down with the back of your hand below his mouth. Allow him to come to you, do not approach him. You are a stranger to him basically if you only see him once a year, he probably doesn't even remember you. If he growls or shows aggression towards you let him be and try again later. If he comes to you when you do this action, then scratch him gently under his chin and leave it at that. A little later try and do the same thing again. Never appraoch a dog with petting it on the head. It's dominance and submissive stuff that dogs are all about and placing your hand on his head is allowing you to be dominant to him. Its something that has to be earned espeically from a stranger. That's why alot of people get bit. They approach from top of the head instead of letting the dog come to you.
How to Approach a Dog Appropriately:
Never approach a strange dog without permission from the owner.
Approach a dog slowly with the back of the hand extended.
Curl your fingers and allow the dog to sniff.
Stroke the dog gently on the chest or shoulder, or under the chin.
Do not pat the dog on the top of the head.
Avoid approaching dogs that are sleeping or eating.
Stand still like a fence post if approached by a strange dog; do not squeal or jump, or wave your arms.
Avoid making direct eye contact with the dog, as this may be interpreted as an act of aggression.
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