Help needed!!!

 Please help!!!
I rescued Bella just over a year ago (she is now 2 and a half) from a home where she was locked in a cage constantly. She lived with other dogs in a foster home before she came to me, and has dog friends that she plays with, without any problems - she even lets them in her home without any fuss.
Ive been taking her to obiedence classes to help with things such as pulling on the lead and going crazy when people knock on the door, and she's developed loads. She really is a very good girl - in fact she's gone from the puupy class to the advanced class in the space of 2 months.

However, she's started to become aggressive with some other dogs. she does this in class, her ears go up and head goes down and i know what we're in for, she'll pull and snap at the other dog - not every dog, and not necessarily the same dog 2 weeks in a row. She's started doing this on walks too, again not every dog - its really very unpredictable.
When the dog handler takes her in class she behaves perfectly (he's a police dog handler) and doesn't take her eyes off him, never snaps!!!

I've been told this could be a respect thing, while she loves me (and my partner), she views us as equals. So the steps I've taken to help this are,
She's now sleeping in the kitchen instead of in our room (which she's fine with)
I've changed my tone with herr - i felt i had 'one tone' so when she was being good it didn't really change from when she was getting wrong.
I've started to give her more attention in the house, lots of cuddles and generally just talking to her, hoping that she'll become more aware of my change in tone when she's done something wrong.

I'm really getting stressed about her snapping at other dogs, which to be honest isn't that bad at the moment but i really want to nip it in the bud. - I know this won't help either as she'll pick up on my stress levels!!!.

Is there anything anyone can suggest I can do, or that I'm doing wrong in the above!!! (When she does snap i give her a sharp tug on the lead and raise my voice and say 'no'). In class I try to use treats as well. She's easily distracted with food (aren't all staffies!!!) but like i say its so unpredicatable I'm often not quick enough to distract her.

Thank you xxx  

Luckily this isn't something I've had to deal with but I know some dogs can just become dog aggressive. I would say concentrating on keeping her attention on you whilst walking is a priority, but it sounds like your already trying to do that. I'm sure some one who can offer more advise will be along shortly  

All I can suggest is you need to read her body language and stop it before it escalates. Not all dogs like all dogs, and Moo is an angel off the lead but a mare on, say passing dogs in the town she will pull towards them, I just learnt a watch command, if she doesn't listen into a sit wait leave command. Its all about the training, yanking on the lead won't help, but there is no magic cure, they don't get on with everyone. Xx

I agree with Janey.

Try working on a command (or two or three) that will distract her from the other dog to you - the "Watch" command or even "sit" or "wait" will do as well.

However, bear in mind that some staffords, even if they've been socialised well from a puppy, will become dog aggressive. It's in their genes.  However, it isn't the end of the world, and it can be controlled quite easily.

Watch her body language; very few dogs go from friendly to attack in the blink of an eye. Usually you'll see a dog start to stare at another (dogs hate staring) and that can cause all sorts of problems. If you see her starting to fix her eyes on another dog, distract her immediately with the watch command & offer a treat. Same if you see another dog staring at her.

Also remember the guy who takes the class will be extremely confident in handling and that will travel down the lead.

I did it myself had a few bad meeting experiences and found myself getting nervous when approaching the same dogs and Ledger in turn was more on alert picking up on my concerns and snapped towards a few dogs, a vicious cycle. Trick was noticing what was happening, working on the 'watch me' command and being hyper aware in the park to give us both time to step out of the way and calmly get his attention on me so he didnt end up under tension on the lead

Thanks everyone. I'lleep working on the watch me technique....and try to chill myself out!!! Hopefully Bella will pick up on that!!!

Its amazing how much they can pick up on your own body language. My lexi is dog aggro, but before i joined this forum i would be quite anxious and i would always pull her to one side and try and hold her while the other person walked past. Now i know that was probably not very good for her mindset lol so now i just pull her on and don't make any fuss about her (i will say LEAVE but thats all) then a huge fuss when shes been good.