In response to the question of whether cat bites/scratches on birds that
"get away" cause the birds to die soon thereafter: in bird rehabbers
experience, yes, quite often. We have gotten birds retrieved by cat owners
who had no obvious breaks in the skin and appeared to be recovering well for
3-5 days, then suddenly keeled over. If we have given the bird antibiotics
promptly after its cat encounter (i.e. within hours) and it was big enough
to receive the antibiotics by injection (robin sized or larger), it has a
pretty good chance of recovering. Right off the top of my head, without
going through our histories, I think about half our cat-got birds die.

Chris Maack
Bird Treatment & Learning Center
Anchorage, AK
btlc at name1.ak.net