Betta fins suddenly shredded

I remember I had this new male in quarantine.
I keep the quarantine fish away from all my other fish.
I was in the kitchen and kept hearing plunk...clunk, plink, plunk,
bonk, etc....repeatedly.
Turns out it was one of the new males trying to get out of his
quarantine container. He was hitting the underside of the lid.
2 yr ago one of my lovely white males jumped through a hole no bigger
than 1/2" wide and little longer. He happened to jump right in front of
sleeping cat. He was "tasted" a bit and then left.
Good thing I found him when I did. He was just laying there, a few
holes in him where the cat had tasted him, bloody and almost all dried
out.
He survived his injuries, amazingly and never jumped through that hole
again! lol
(I didn't punish the cat as she did nonthing wrong. I mean heck, a fish
falls out of the sky and all, hehe.
She could have eaten him, or killed him, but she didn't. She just had a
taste and then went back to sleep. = )~