problems stripping fox tails

So trapping the high country above the ranch for cats and coyotes, picking up some nice dogs and one good cat. I have never trapped that elevation before this time of the year but on snow machine its fun and no completion. What has surprised me are the amount of Red fox up there. I have caught 3 now and they are awesome heavy fur and dark red for this county. Ok problem is the first fox was frozen in a snare and got back thawed it and when I stripped the tail the last third just fell apart. Ok thought it was frost bit and that is why it happened. The next was snared by the hind legs and alive, stripped the tail same thing, last 1/3 of the tail just came apart. Today got another and I have seen a bunch of fox but this one blew my mind biggest darkest and heaviest fox I have ever seen 8,300 foot elevation. I thought this one is going to the taxidermist, 1st day catch very alive in a foot hold very little paw damage. Went to skin it same dang thing on the tail!! No indication of frost bite, tail was limber and I kept it in a canvas bag in the sled. Paws still limber when I began to skin. The only other thing I can think is the tails are so heavy, at least half again as a prairie fox the tail stripper is not working right. Any ideas or thoughts, I have put up at least 1000 fox in 50 years and it has got me stumped and upset.

I've seen that on late season overprime fox.The fur is so heavy and the skin is so thin on the end of the tail like tissue paper that the tail just falls apart,seems to happen on the end 3rd of the tail.Never seen it in a December fox,usually mid to end of february or some years starts end of January.
You will usually have half or 2/3rds of the tail left and they look good and wont be downgraded.

Well I think your right too much fur as far as over prime what would that be?? These have all the guard hair and no under fur showing I did buy a fur dressed Alaskan fox while visiting and these 3 fox would rival that one just awesome fox. I almost think these might be a genetic group different than our low land fox the feet seem larger and they out weigh them also. Not sure how they can keep the weight on no big game up there to winter kill but they are fatter than fall fox. I do agree the skin on the tail is thinner than wax paper.

Good question since I just had it happen to me for the first time ever on a fox I took last week. I lost about 4 inches off the end of the tail and that was the white tip. The rest of the tail looks fine, though. I thought maybe the hole I was drawing it though was a little too big (or too small?) I draw it through the hole on a pair of pliers and open or close it accordingly. I have never had a problem before with this with any critter.

that will not hurt the value of the fox they dont use the tail.

Colt fur fur buyers say since fox are so low in price the tail damaged will cut the price in half. $5 fox??

I had the same trouble this year but hadn't asked the question yet. I think it happened on 3 out of 28 fox. It's happened a couple times in the past too. The first one was in mid November the other two were December I think.

That used to happen to me on occasion with Cascade red fox, usually late season, no fat on the animal. I think they actually start to "consume" their skin when they become nutritionally challenged.