Question about dog behaviour

So three years ago we adopted our female Lab/Golden, she was almost a year old at that time. She is a very sweet girl, excellent with the children, even if they get rough with her she doesn't do anything. She gets along very well with other dogs too, my father in law has two dogs around her size and she's great friends with them.

A few months ago, we brought home a smaller male dog (Jack Russell mix). She had spent time with him a few times before, and really enjoyed being with him. Now that he is with us, they get along excellent and spend a lot of time playing with each other. However, our Lab has a bad habit of grabbing the smaller dog by the neck and dragging him around, particularly when they are outside. She doesn't seem to be doing it aggressively...it's almost like she's trying to corral him as if he were a puppy wandering off. She never is ever aggressive with anyone, including him, but obviously due to the size difference I am concerned that she might be hurting him, or that this might be behaviour that needs to be corrected. He never complains about it when she acts this way, and I know he will complain if she gets too rough or if the kids accidentally step on him. Thoughts?

I know that often for both dogs and cats, if there's a new pet introduced, the old pet will try to show dominance in some way, shape or form. When I got Sherry (my second cat, a small Russian Blue), I had had my other cat Sprinkles (a larger calico) for two years. Although they were the same age, once the swatting and growling had mostly subsided, Sprinkles would sometimes pin Sherry to the ground (she is easily half again Sherry's size) and wash her, like a mama cat will with her kittens. It sounds like your dog is doing something similar by carrying your new dog around like a puppy, even if he is by no means a puppy! I know other people who have multiple dogs where one will mount the others (even if they're all fixed or all the same sex) as a show of dominance as well, so maybe it's an expression of that?

I wouldn't get too worried about it unless your Jack is. Frankly I'm surprised he'll let her do that anyways! Jack's are dominant little dogs usually.
Your Lab/golden probably thinks he's her baby. :) You can tell her to drop him if it really bothers you or you're concerned.

I agree with MQ - it sounds as if she is protecting him.

I wouldn't allow it. Even if the smaller dog isn't complaining doesn't mean it's not a pain in his butt to be dragged.

Just because she hasn't hurt him it's still possible that she will, and it's not something I would allow considering the size difference.

Yes Jacks are tough, as others have pointed out...but that doesn't mean they should be played with roughly. They are still small dogs.

I wouldnt worry about it, its part of their breed to mouth things ever so gently. Probably just "retrieving" the little dog.
Im sure if the jack russell got tired of it, he would put your lab in its place pretty quick.

We have 2 dogs - a mini-poodle we've had for 6 years and a mini-schnauzer that we've had for almost a year. Both "fixed" males. The poodle has finally gotten past the "don't touch me" phase to the "I'll show you who's boss" phase. They "wrestle" frequently with growling sounds from the poodle but the schnauzer ususally initiates it - but he usually "gives up" and flips over on his back. I watch them carefully to make sure no one is being hurt and sometimes break them up but they seem to be "playing". The poodle will occasionally try to grab the schnauzer by back of the neck and I him stop him because a "shake" can do a lot of damage. Shaking is how they kill their prey. (at our house, that's usually the towel I use to wipe his paws or their toy but I've seen a dog kill a groundhog that way.) Usually he just chews on the schnauzer's beard. I don't know if I've been any help at all. I'd say - keep a close eye out.

I actually have the opposite problem. I have a 100 lb. lab/rottie. My (giant 26 lb) Jack Russell graps on to the side of her face and hangs off it. . !! lol I know if she was ticked off with him, she'd put him in his place, but she just tolerates it. She knows he's a playful puppy and just puts up with him. I think it's much like any social behavior. . . Give and take.