Anyone own a Longhorn Cowfish?

[badfish!]

I had a cowfish that when it was in the process of dieing, he got his horns caught in the powerhead in my tank, I think that stressed him even more and I'm sure he released toxin, but I ran carbon and did a few large water changes (not to mention I removed him to another container in the sump) and everything else survived, all the other tank mates didnt look good, but all pulled through. A couple of years ago when I had my first salt water tank I had a helmet cowfish and when doing a water change with the gravel syphon, I nicked him (they are so curious, they need to be right where you are doing something so they can see). I guess the nick was enough to stress him out, and I didnt know any better and within a couple of days everything in the tank was dead.