The first one we gave careful nursing to for about a week after his injury, but he got ever worse. We took him, on our vet's advice, to the Animal Health lab. They saw him still alive to see symptoms, then euthanised him and did a necropsy. All they could find was chemical tracers of muscle damage so they assumed death by fighting. Two more over the following months had exactly the same symptoms (which looked like head injury to me) so we shot them, the fourth had his leg badly broken, also shot. The only tup seen to be aggressive was the new one, the others had been together for a few years, very friendly with each other. He has reportedly settled in well - different situation, different mix of other animals he's with. Had he been vicious or dangerous to people we would not have sold him on - you will see in previous posts that is what I advise. I think he simply didn't like the tups he was with and was otherwise an excellent tup. He had come from a very extensive set-up (open hill) to our smaller set up (fenced) so perhaps he felt too confined.
Yes, we did once have that happen, where 2 shearling tups got their side horns tangled together. Another big vet expense as they both had to have bleeding stopped and wounds protected. One eventually died, the other we still have several years later, in fact he is our senior tup, now 3 horned. The reason we seem to have quite so many tups around is that because we breed breeding stock, not specifically for meat, we keep our male lambs entire and keep them until 16 months. Any which are suitable for breeding are either kept or sold at that point and the rest go for slaughter and end up in our freezer. Meanwhile, the hoggs become shearlings and are all very enthusiastic to prove their maleness. For the older tups, it's like having a load of rambunctious teenagers just past puberty around. We don't have room to keep them separated by age, and last year is the first we have had a big problem.
As you can imagine, if a 4 horned tup fights with a 2 horned tup then it's an unequal contest, but more dangerous to the 2 horned (we no longer have any 2 horned tups of any breed). When 4 horned tups fight, which ours don't often do, they tend to go for the sides, as deer do, so internal injuries can happen. Also eyes can be lost. That's why we breed for non-fighters. There is evidence that black multihorned tups from Britain were used by the Romans in the arena!
If you are wondering why we have several tups at once, it's for biodiversity in a very rare breed, Ancient Type Hebrideans, as opposed to Modern Type Hebs. Our tups have only a handful of ewes each.