I think I was at fault today.

I took Diesel over to the field today to let him have a run around in the stream as we've had some nice weather. We caught the attention of a lady walking an American Bulldog who came over the him, I put Diesel back on his lead when I saw them approach, Diesel saw the ABD heading our way and he submissive laid flat on his front with his nose to the ground, the lady asked if it was Ok if the ABD came and said hello, as Diesel appeared to be of no threat to the other dog, we let them meet, they were sniffing each otherbut I felt really worried then Diesel starting growling at the other dog, as I've only had Diesel a matter of weeks, I don't truly know him. I found myself keeping a tight tension on the lead as I was worried, could this have been the cause of him growling at the Dog? I apologised to the lady and she said it's Ok because it probably because he's on the lead. This is my first bull breed dog, I grew up with little Jack Russells, hence why I probably worried, to me he is a big dog.

Could well have been the tension and worry through the lead, that caused this reaction. A long as he was on lead no worries and no harm done. I find sometimes a quick hello and move on as sometimes too much at once can be a little uncertain for either dog

True

You did exactly the right thing by putting him on the lead, always the best thing to do when unknown dogs are about. You will learn through Diesels body language what signs mean what over time.

You are also correct with the lead tension, they pick up on it really easily but again this will get better for you with time and trust

Took Diesel for his evening walk before he settled down for the night, this time we met a little terrier, Diesel done the same thing as earlier today, he laid flat on the ground, I've read somewhere this is a calming signal? This time I was very relaxed with Diesel, came him plenty of slack on the lead, used a calm and friendly with him and the Terrier, they started sniffing each other then the Terrier just lost it and starting yapping at Diesel which caused him to lunge, I said no to him which stopped him then I lead him away. Maybe the terrier just wasn't very sociable?

Sounds like Deisel is a very well balanced dog. The loose lead seemed to help so something learnt

As for the terrier, well it's not just them that can be snappy hence my mentioning on lead introductions first. Deisel stopping when you called him is fab, sounds like he has had some good training in the past or he's just simply smart

Lying down can mean lots of things - it can be a calming signal but it can also mean that he is worried and protecting his vulnerable tummy area - herding breeds also tend to lie down when they're "stalking" other dogs. My dog lies down when she sees dogs - but it they approach she will lunge/bark/snap (she's fear aggressive/defensive).

What's the rest of his body doing? Does he seem happy/curious or tense? Does he stare when he does this? Can you distract him? Tension on the lead will cause tension within your dog, this is correct. I think it's pretty normal for a dog to react when another dog is volatile to them (I.e the terrier yapping!) may have been the other dogs problem, or he may have been picking up some tension from your dog. It's trial and error along with reading body language really - as long as you keep your dog and others safe in the process. Agree with putting him back on lead when strange dogs approach, though. Some people aren't always honest about their dog's own sociability and would allow behaviours from them that you, yourself, may not.

Now that you have mentioned it I recall Diesel shivering? When he was on the ground when the Bulldog came over, I brushed it off because I thought it was because he was wet and I let him have a splash about in the stream, he came from a home with other dogs and before he came to me, he stayed with the owner of his son and her other two dogs and was completely fine for the few days he was there. So I think I am just presuming he will be Ok with other dogs. I am keen for him to find friends to play with as I do worry he might be a little lonely as he is in a home by himself now.

The shivering may have been excited tension, or maybe nervous tension. Some dogs live with other dogs but don't get walked very often so aren't used to the "meet and greet" My girly can live with other dogs that she trusts no problem, but cant cope with meeting random dogs. The more positive interactions he has the better - but remember not all dogs will get on, the same as not all humans would. They all have very individual personalities/interaction styles aim for positivity but don't feel sad if it's not 100%

Haha, agreed. I think we'll steer clear of the little terriers, in our travels we noticed they're quite brave when they see Diesel. When I first took Diesel in, we went for a walk and came across a young blue staff, who was giving off all the play signals and seemed very excited about Diesels presence, Diesel was very excited himself but because Diesel towered over her and I had just took him in so didn't know him too well, we carried on walking, to think about it most other dogs don't even bat an eyelid at him, I think I should pay close attention to th strange dogs body language before I approach. I think it would be nice to see and perhaps interact with the blue pup now I trust Diesel a lot more.

Also I would say don't look at growling as a negative thing it is a way for dogs to communicate. In the incident with the bulldog your dog could have just been telling the other dog he was uncomfortable and it should give him more space. Its how they communicate

Lots of wise words above!

One thing that might be worth doing from now on is building up positive feelings towards other dogs. So when you see one, you go into 'hey that's great, another dog!' mode, have a happy voice and use plenty of treats when Diesel's being positive.

I personally wouldn't worry about close up greetings at the moment. Just work towards you both feeling positive and relax near other dogs first, then you'll have a better basis for harder stuff.

It does, though, sound like you've got a great dog there. He's communicating well but without being OTT about it. Just keep reading him and responding in a way that encourages good behaviour, and always spot when he's trying to do the right thing and reward it. You'll get there!

Cant add anything. All great advice above.
Just wanted to add, with Pixee, shes not DA, but more FA when on lead. She copes so much better off lead in big open spaces, as she can get away, her recall is good, so I dont worry. I do always put her on lead,in cetain situations and close spaces, e.g. the canal, just so shes under control and cant get blamed for snapping back, barking, growling should it happen. I am all for doggy talk, some people sadly are not and take growling as a threat for the wrong reasons, its just as Rachel says, doggy talk, that dogs alone understand. Diesel comes across as a good dog, you are still learning from him, and him from you.

Don't be too hard on him, he is doing his job, protecting you. You have done right every time, he sounds a wonderful friend