Is this a sign my puppy is aggressive?

Hi I was just looking for a bit of advice. Nyla is now 5 months old - we did not get her directly from breeder and left her mother at around 6 weeks. . She's is in the process of puppy classes with a 10mnth old husky pup which she adores and loves to play with. She also loves the neighbours dog which is a lab collie mix. She happily passes other dogs on walks and is always keen to go so hello however she can is always really rough. She's a very bouncy playful pup that just wants to say hello to everyone but is still very excitable.
Today we thought taking her into the pet shop would have been a good idea- a small pug approached Nyla and usual tail wagging trying to get over to see the pug. (This is the first time she's met a dog smaller than her) things seemed to be fine and then the next minute Nyla grabbed the pup by the scruff of the neck and was growling (which she can someone times does when she's playing tug etc) I tried to take Nyla away but the leads were caught and the other woman just stood there so I picked Nyla up with her harness but she still had the pups neck and the other woman took her pup which then yelped. The wee pug was absolutely fine and Nyla then tried to walk towards her again with tail wagging which didn't appear in a threatening way?! But I don't want to be blinded by my love for my puppy but I'm so confused if this is a sign of aggression.
The pug tried to get underneath her while sitting and knocked her over a little before she snapped
Her tail seemed to be wagging while she held the pug up off the floor but the scruff of the neck
Her body didn't seem tense as soon as I picked her up my partner said her legs were all floppy
Is my puppy a big bully any advise would be appreciated (sorry for the long blab)

After the long blab I'll do a short reply

Sounds like you've read Nyla's body language correctly, if she was relaxed she was playing. Staffs play rough even when young and she may well have seen it as simply that. If anything, you've learnt that she will play rough and smaller dogs may not be so able to cope with this behaviour so now that you have seen it try and train it out of her now whilst young.

If you're in a similar position again approach with caution and if you see Nyla trying to be rough pull her back make her sit and calm down then let her approach again obviously on lead. It will take a little time to train but with consistency you will get there.

I have the same trouble with Gizmo, but he also tends to smack other dogs in the face with a paw if he can.

Haha thanks Ian. It was such a horrible experience but we have lots more puppy classes so we will be working on this too!
It's a quicky one with no quick fix. Smack with a paw

I agree, it sounds like puppy play. It might be useful to make sure you've got 'leave it' nailed, so that if this sort of thing happens again you can just give a happy 'leave it' and have Nyla sitting quitely for her treat in response.

Good advice above

Sound slike play to me as well. Suki will do this with smaller dogs as well. We keep a can of pet corrector on hand in case she gets too rough

Here is a link about body language tht will help

http://staffy-bull-terrier.com/dog_body_language

Thank you all for your advise. I just read the link and also Suzanne Colthiers article and feel I understand much more. I wasn't paying enough attention to Nyla to ready her body language and realise she was uncomfortable. I also don't thinnk she has the best manners herself! We have plenty to work on but feeling positive again thanks to all the people that have replied to my post

We had the exact same thing with Harrie although she was a bit older French bulldogs seamed to be her favourite target and also a Beagle at the park.

Luckily the beagles owner is a nice lady that was willing to work so the dogs could play together and the problem has been sorted you have to keep and eye out for when the behaviour starts jump in fast give the dog a "stern no" and as above put it on the leash.

Cheers

when she meets new dogs you could try letting her say hello as soon as she interacts with the other dog call her back say good girl and give her a treat, let her say hello again and repeat, each time letting her play for a little longer. she will soon learn that its ok to say hello but if she gets called away she will get a nice treat and lots of praise.

this really worked with howie 9 times out of ten he will just sniff another dog then without calling him he will come up for a treat.