Thanks Jackbox,

That was exactly my reason for asking. I didn't know how negative they were and I would not like to associate anything negative with the aggression.

elmac, a water pistol is definitely not a good idea in my opinion - as Jackbox says, if your dog associates the squirt of water with other dogs rather than it's own behaviour, it can fuel the aggression.

I've managed to watch Takara closely and observe the signals she gives off.
As with most dogs, she gives off minute signals to say she's uncomfortable. Things that you probably wouldn't notice unless you looked for it specifically.
She raises her hackles at first but that doesn't mean the aggression is about to start, she moves her face to the side to say 'I'm not a threat' but she won't go into a low submissive posture in case she does need to defend herself.

However, there is a tiny change in her behaviour before she begins to snap and I can't really explain it. As soon as I see it I praise her and walk on calmly. This is our first step - we will start to just walk a little further and then approach again when she's more comfortable with it.

Eventually I hope to be able to teach her to sit by my side when she's not comfortable with a situation so that I can then remove her before she starts to snap.

It depends how your dog reacts, is it from a distance or only on meeting dogs?

Again - thanks Jackbox, that was all I wanted to know!
CLMG - we have used the rattle bottle before for lead walking (had to stop when I got Eddy and he nearly pooped himself) but I wouldn't want to frighten other dogs as the proximity is quite close when the aggression occurs.

It is when we are approaching dogs in the street and both dogs are on lead, on the same pavement. He normally doesn't bother if they are the other side of the street. Also off lead sometimes after all the sniffing business is over and he has decided he doesn't like them or he wants to scare them which he usually does and they run off and that's it over unless the other dog decides to have a go when he braves it out for a bit and then comes whimpering to me esp if other dog has nipped or given him a good scare. He has never damaged another dog but I don't like the violence of it and I want to stop it if I can. We have had him neutered 3 weeks ago but no change as yet.

We have the same sort of problem with Jack, he can say hello nicely then have a go, and a lot of the time we've found, and I know you'll laugh at this, but we say to Jack 'be nice know' and he is maybe it's the way it's said i don't know, but as far as the neutering goes, it's far to early for it to have made a difference, Jack was done on March 20th, and tonight was the first time we really noticed a big change in him, another dog at agility came flying up to him snarling and snapping, and instead of having a go back, he turned and fled behind Christopher, so give it time.

Hi elmac,

Geez... he sounds just like Eddy used to be!
It's far too late for me to post comprehensibly though so I will give my ideas on it tomorrow, if that's ok?

If the aggression is anything like my GSDs was, then you will find the discs are just worthless. The dog is so transfixed on the target that it just fails to hear them. I think it really does depend on the extent and the type of the aggression.

Sam does not even seem to be aware that I am there when he sees a dog on lead walking toward him and he paid no attention to the discs at all. After he has done his lunging and snarling he turns round to me and wags his tail and grins! I think he enjoys it!