Hi there and welcome! Polar bear sounds utterly adorable, and what a fabulous life you share together. It sounds quite wonderful.

Re the attacks, I am not a behavioural expert, so just speaking from my own experience and what I have picked up from others on the site. In my view (and please take it for what it's worth...) it is most unlikely that these attacks have anything to do with Polar Bear's missing leg. I just don't think dogs think about each other in that way. I have never had the slightest indication that other dogs perceive my Meg as being in anyway different because she is missing a front leg.

What dogs certainly do pick up on though is the energy other dogs (and humans) give off and also the calming (or otherwise) signals they give off using facial expressions, ears, tail, coat, yawning, turning away and so on. It can be extremely hard for us to see it, quite simply because we are apes and they are canines and we are programmed differently. My suspicion would be that as Polar Bear spent his early life in an abusive home his needs in terms of socialisation with other dogs at a young age may not have been met. I speak from experience here, as this was certainly the case with my Meg, who was also rescued from an abusive environment. This may mean that he missed out on all the playing, play fighting etc etc which pups use to learn how to communicate with each other. If he doesn't know how to give off appropriate calming signals when meeting other dogs, they may perceive him as a threat, even though he is certainly not aggressive or intending to instigate anything, quite the reverse, in fact. If he has been attacked a few times, as you say, (let alone his experience in the trap), then he will also be showing tension and fear, which can also be a trigger for some dogs.

I think it might be really helpful if you were able to find a behaviourist to work with, if there is anyone in your area (not a dog trainer, but a certified animal behaviourist), and perhaps to introduce him to a strictly controlled and well managed group environment. There are places in the UK that run groups specifically for nervous dogs, which might be helpful in this situation, but you'd probably want to see the behaviourist on your own first. If you know dogs that he is okay with, then I would also spend as much time as you can with them to help build his confidence. Also, would it be possible to fence your yard (or a part of it) securely, so no other dog would be able to come in and Polar Bear can have a place where he knows he is safe and secure.

The great news is that (if my instincts are right) this is an eminently soluble problem. Unlike if it were on account of his leg, which there's not much we can do about, these signals can absolutely be taught to an adult dog. It may take them longer than a pup to pick them up, but certainly they can learn how to communicate with confidence. You might be interested to take a look at the work of the Norwegian behaviourist Turid Rugaas, who's done a lot of work in this area. She published a book on calming signals, which I found really helpful with Meg, though I'm sure other dog walkers though I was bonkers, as I attempted to imitate them myself in an effort to reassure her...

Good luck, and please do stay connected, and let us know how you and Polar Bear get on.

Warmest wishes,

Meg, Clare and Elsie Pie xxx