Ronan the wonder kitty... not so invincable!

So we came home from our camping trip to a very loving, happy to see us kitty. Soon after we walked in the door, Brenna was in feeding the cat, and soon realized something just wasn't right. She comes running outside as Bill and I are unloading the truck, with total terror in her face and says "MOMMY, I think Ronan is hurt!" So I ask her where and she says on his back... I quickly go in to see what she is talking about, and sure enough, under his mass amounts of hair he has a laceration nearly an inch deep, full of puss, and stinky as hell! EWWW! So, I then go to my neighbors house who was feeding him for us while we were gone and asked her if she noticed anything out of sorts and she felt awful that she hadn't noticed, but really with the hair covering it... she really couldn't have very easily. Ronan was outside when we left and that night she let him in and fed him... so sometime between then, it seems as if he got stuck while trying to crawl under something and sliced open his back. We took him to the vet yesterday, and because the wound had been open and exposed for as long as it had, his tissues inside were dying and it was infected. He underwent a minor surgery yesterday to cut out the dying skin... and they wanted to close it and put in a drain, but I just could afford another 100 plus dollars we were already in 215 bucks. So they left it exposed and he is wearing a cone. He has to wear the cone until the scabbing is off and the scar is pink... so for awhile. It is going to take some time for the gaping hole to fill in with new tissue. I feel so bad, and wish we could have done more... but at least we know it is no longer infected, and he has anti-biotics to prevent any further infection. I think we just may invest in some animal insurance...