I work with a lot dogs that have aggression problems. The most common cause of aggression is fear, and one common cause of fear is attention from humans. Why?
Sometimes dogs are afraid of human attention because they’ve learned from unfortunate experience that it means they’re likely to be yelled at or hurt. Other times dogs are afraid of human attention because they’re genetically shy, and anyone new/unknown feels threatening. Sometimes it’s both. Either way, if the fear is strong enough, a dog can feel the need to protect herself.
One simple technique that can help some dogs suffering from this very unpleasant condition is to avoid looking at them – ignoring them and behaving as if they’re simply not in the area until they get used to you. Clients with a small breed dog prone to ferocious barking when visitors understandably look at and talk to him (“Hey – he’s a cutie!”) started telling guests, “Pretend we don’t have a dog.” This gave their little guy a chance to get used to the visitors and check them out without being overwhelmed with eye contact, talk, and being reached for from way up high. After a few minutes, guests would toss a few treats for the dog to pick up, then add just a bit of quiet attention, and from there the dog was able to relax and meet them with no difficulty.
Of course this won’t be enough to help every fearful dog. If a dog is standoffish, tense, or growls, gently back away and give her space. Hold off on introductions, confine the dog behind a closed door, and consider consulting with a certified trainer educated in and experienced with aggression cases (and who only uses gentle, force-free methods).
Being slow and gentle when offering attention is a great suggestion for meeting any dog. Until a dog seems to ask for your attention with happy/wiggly body language, see what happens if you pretend the dog isn’t there at first.