Hi all, sorry for the long post but I really need help and I want you to have the full picture and I want to be truthful. Our family got a Border Collie, now 3yo, when he was 8 weeks. I've always had rescues which have had issues (food aggression) and having 2 small children, we decided not to have a rescue for the safety of the children. After we got him, I took him to puppy socialisation classes, in the vets, in the park, on the beach etc and I learned a lot about how to manage him. I then took him to bronze formal classes for obedience and he did very well, he walks to heel, he will run with me, he takes direction - left, right, on, stop, wait, leave etc. Then, he got quite bold and I started not trusting him around other dogs, he had a go at a horse at the obedience classes and I stopped going. The lady there suggested that he be neutered before his hormones kicked in fully as if they did "he would do anything to get to a bitch". So I took him to be neutered. When I picked him up, the vet nurse came to talk to me and told me that he was horrible and he'd been really aggressive with them - snarling biting etc. I was VERY surprised as we'd not seen this level of behaviour previously. Turns out, they'd given him a premed and put him back into a cage for it to take effect, as they'd gone back in to get him, he was cornered and became aggressive. Everytime I've been back to the vets since, he's lunged at the vet, the first time, I got a muzzle on him (as it was given to me and I felt I had no other choice - for his injection to be given) and he quietly had his immunisations no problem, but now he's scared of muzzles (understandably). I have worked with him in the house on it, with positive association, treats and love around the muzzle and I can get it nearer everytime but I'm scared he'll lash out. After the altercation with the vets the first time, I took him out with my children and there were other children there, he got out of the car and started barking and snarling at other children, I walked him away and reassured him but he seemed scared and nervous. I took him out to a country park with my family and stood with him while they played in the children's play area, a friend of a friend, all bravado, comes over and asks to stroke him, I say no point blank, I'm just too scared of him actually hurting someone now. The guy says, "all dogs love me, there's no way there's a dog in the world who doesn't love me! I'll convert him." I say no and beg him to stay away but he keeps coming, I walk away but the guy is insistent, he bends down as we are walking away and gets a finger nipped. He admits it's his own fault but it doesn't matter, my dog has bitten someone and I am mortified. He was in the boot of the car, in his travel crate and a little girl had slipped off behind the car (I know, I should have closed the boot, but I didn't) he's growling and bearing his teeth at her. Outside the children's playground and he's growling at children inside. I can't take him anywhere without fear that he will hurt someone anymore. Everytime dog feels cornered, he becomes aggressive (which I understand after what he's been through). We have a relatively small house and there are lots of places where he can feel trapped. The crux of it is, I'm anxious, on pins that he is going to hurt one of our children. I got him because it had been 2 years since our previous dog had passed away and I felt ready, emotionally, financially and time-wise, to dedicate it to this dog. Now I don't know what more I can do. I have taken advice from a dog behaviourist who said that it's natural and normal to be happy with your own and not so sure when outside, which I understand but it's now impeeding our lives because we can't take him anywhere there is likely to be other people (I walk him very early or very late to avoid others), I appreciate it may be just what he needs but I'm not willing to risk it. I can't even think about getting rid of him, I do love him, what can I do to help him? He's very scared of everything but I'm scared that his fear will be miss-placed and he will hurt one of my children, We can't carry on living like this, scared in our own home. If anyone has any suggestions, we would welcome them as we're at the end of our tethers now.