Luke demonstrates a mannerly greeting; he is turned sideways.
Today I had the poodles out together; as you know they don't often go on a walk at the same time. Not because I don't enjoy having all my dogs together but they walk at very different speeds. The difference between Tilley and Luke is the widest; Luke is a sprinter and Tilley..................well let's just say that the local neighborhood snail would outrun her easily. So when I do take them together I resemble a propeller just before take off. Right arm out front, left arm out back coaxing Tilley to come along. Funny how she walks soooooo slow but get a tennis ball out and she can amazingly run very fast after it. Oh well.
So today as we were about half way around the park we were coming up on a Wheaten looking mix. I'd seen him/her as we got out of the car. With old dogs I always scan like crazy; we cannot afford to have even a very friendly rambunctious dog run up on us. Actually I always scan; even when they are young, I don't like surprises. So we were heading that way and Luke was sniffing, trying to assess the dog. The dog was stiff; I'd noticed that way back. The dog would not move for the owner; she'd tried several times to get walking but the dog just lay back down.
As we got closer and closer I could see Luke stiffen up; he didn't like the looks of this dog's body language and he was right on. I told Luke to "leave it" as we walked by, he immediately turned his head away as the dog started with a fierce display. I praised Luke like mad and he strut on past without a glance back. As we walked past I noticed that the dog had hair over it's eyes; it could barely see. It could see well enough and smell to know that dogs were coming but it could not see perfectly. Dogs who have their vision impaired by hair can often be aggressive. They aren't really truly aggressive; just sort of defensive just in case sort of thing.
I remember seeing a rescue video several months back of a hairy little beast; the dogs hair completely covered his eyes and he was displaying aggressively. They quickly cut the hair around his eyes so that he could see and the displaying stopped. Dogs don't like when they can't see properly; and it can put them on the defense when they might otherwise be fine. Whatever the dog was signaling; Luke wasn't buying and was none too impressed. He will typically display back to a dog like this unless the dog is simply an annoyance more than a real threat. They just know.
You really do need to be watching at all times; watching your dog and watching the other dog. There is a lot being said and if you aren't paying attention you will miss it and be left saying "what was that all about?"