Thank you everyone. If you haven't saw it, I set up a memorial for him in the memorial section.
I've spent awhile sitting with Smudge. I sat the dust bath in his cage, but he won't bathe. He's just sitting in it. I feel bad for him. I don't blame him for what he did. But I think he knows that Mako is gone, and is just as sad as I am. I'm not sure why else he wouldn't take a bath- he's usually the first to jump in and roll like crazy.
I've cleaned up the blood..and tried cleaning Smudge up as well. Needless to say, Smudge will remain an only chin from now on. There were no warning signs. I just can not risk something like this again with him. He will still have company through the chins in the cage next to him..but that's it.
Like I said, I hope this story will help people understand just why it's so important to have a good vet on hand, and always be prepared with cage mates just randomly turning on each other...last night, Smudge and Mako were grooming and cuddling happily. They were always smooshed together snoozing, and were the most bonded out of any of my chins. Today, Mako is gone.