Anyone heard of witnessed

Weakness.

I'v heard a few stories and the one I heard was off my lecture in college he breeds and shows springer spaniels one time he was walking about 15 of them over the fields all dogs related and get along great nice family group. Well he opened one of the main gates and carried on walking about 100 yards away dogs some distance behind him but gernerally following him,He heard the gate shut with a bang then heard a dog screaming, all the other dogs exept that one was around him by then, then they all shot back to the gate to the other dog in pain and tore into it before he could get there. It turned out the dogs leg got jammed in the gate and the gate locked which is why the dog wouldn't stop screaming by the time he got there the other dogs had killed it. Now these dogs are extremely well trained and has never showed any sign of aggression/fear/dominance nothing he asked professionals and they simply said they turned primal and eliminated a source of weakness.

I've never witnessed it with dogs, but my cat (Ziggy) got her leg caught in an upturned table leg once and was wailing and crying. I went over to try and help her get out and my other cat (Bowie, who is normally very sweet) attacked Ziggy and I. Ziggy got out unscathed and they were cuddling and loving each other again within the hour. I had some pretty bad scratches and bites, but they healed quickly. It was very scary, but I know it could have been a lot worse if I wasn't there to get her unstuck. We put the table outside to keep it from happening again.

It's scary and I don't really understand why animals attack rather than trying to help.

Yes ive heard about that poor poor dog

I've never heard of it, but in the wild, I can imagine it's more to do with a weak animal attracting the attention of a predator, so they turn and attack it.

never seen it in dogs but a couple ov years back i saw a cat get clipped by a car and it ranb off limping only to be attacked by a couple ov other cats