To Much Inbreeding Or Not??

[dunkers87 5]

I have a polecat jill with a tail about 2 inch's long, I was told that it got bit off by another ferret But I think it might be to much inbreeding which is the cause. I know if ferrets are inbred to much you start getting deformity's in the young like short tails etc. But is there any other way of me telling or not, as i want to breed from her next year as she's a cracking worker, but obviously not if it is a deformity. Thanks in advance.

[The one 8,618]

I had two but the lad i got them off had a hutch with a lid on the top ,don't know if he was a clumsy barstool as they where different litters in different year he effectively docked