Ive done load's of it over the year's and never lost a ferret to rat bite's seen some bad bite's and a missing tail one time..they do eventually jib but they still good for bunnies after that...i used to use net's on awkward spot's and i can remember one time having a ferret and a rat in a net at the same time.. ..good job the terrier's where well broken to ferret's..
On the jaundice side of thing's i have lost a terrier to it at 8yr's old..but when they get put among hundred's of rat's over a long period of time anything can happen..