[pi1otguy]

At the dog park I've seen small 7 lb dogs try to guard their human against other small dogs. I've seen them do the same to 30 lb dogs except that they are often ignored by the larger dog.
I've seen large breed puppies (7 months) basically run over small dogs as if they don't understand that they are big. And of course there is the ~20 lb dog who "bullies" or corrects the 60 lb dog.

Are dogs unable or unwilling to notice size differences? Are there other cues that makes size unimportant?

 

[Wicket]

I don't think it's about "size" but about "state of mind". It's how the dog carries itself, and what kind of attitude it has. This is why you see examples of small dogs being able to control big dogs. Size plays no importance, and this is why sometimes you have to train a big dog to be gentle will little dogs. To them, a dog is a dog so they play how they know. And with puppies, they will pretty much run over anything in my opinion, LOL.

 

[Hambonez]

My 13 lbs puppy doesn't try to guard me against anything, but he is very aware of his size when playing with other dogs. When he's playing with smaller puppies, he doesn't throw his weight around. He'll pin them when they wrestle, but he's standing over them, and will pop up off of them every few seconds to let them get back up. Sometimes he'll put his head low or roll over onto his back so they can jump on him too. When he plays with bigger dogs he goes all in. He'll just throw himself at them with all his force. It's really pretty interesting to watch. He's been in multiple play groups for several months where he can run around off leash with other puppies and dogs, so he's had a lot of practice!

 

[KBLover]

Are there other cues that makes size unimportant?

I think it's mostly this, though I think size does matter.

I do think dogs perceive size (or at least Wally does because things that are small and over his head - he's curious, I hold a box over his head and he's like "oh HELL no!" and moves away. Now, if that box looks like it's a big as the world itself or just as big as I see it...good question.

With dogs (and people) size seems to matter here too. Kids, he's typically okay with, adults - not as much (unless they don't bend over him - triggering that "that's big and over my head. No. No. No. No. NO. Hell no! NO. No." response - or have food. Food > all else to him). Small dogs, he's more apt to look eye to eye/nose-to-nose with. Bigger dogs and he's staying near me. So, at least for him, size seems to be more about "how high over my head is it?"

Haven't figured out why some big objects on the floor disturb him, though. It's a size thing, or maybe a shape thing - or both?

 

[JohnnyBandit]

It is not the size of the dog in the fight but rather the size of the fight in the dog....

 

[Jacksons Mom]

Hard to say.

I think it depends on the dog too.

Jackson definitely knows his size. When it comes to bigger dogs rough housing and such, he tends to stay out of the way. He's very aware that he is smaller and could potentially get hurt, but he's also very aware when a dog is just wanting to gently play with him, or whatever and has no problems playing with big dogs.

But he's just really good at assessing any types of situations that he may or may not get himself into.

 

[lil_fuzzy]

Obi seems to play nicer with dogs that are bigger than him. He bullies dogs his own size, and it's like he knows he can't get away with it with bigger dogs.

Pixie only likes dogs that are smaller than her. If they are white fluffies like herself she will tolerate that they're slightly bigger. But any other big dog approaching really scares her, while a small dog approaching is something exciting. She was attacked by a big dog a couple of years ago, so no matter how friendly and submissive the big dog is, she will growl if it approaches. But any bouncy, playful small dog is fine.

I think they do know their own size in relation to other things, but how they react is about the dog's state of mind and previous experiences, and probably other things too.