From:
sukiec@optonline.com
Date: 2003-04-18 19:38:03 UTC
Subject: Re: [ferrethealth] re: Lifespans
To: ferrethealth@smartgroups.com
Message-ID: <28502609.1050694683964.JavaMail.root@scandium>
Well, I think that you have asked some of the unanswerable questions that exist in relation to life span.
Certainly, a number of us have been very concerned about the tendence to breed mostly for appearance among so many (perhaps most?) breeders and what impacts that may have.
In relation to neural crest genetic disorders (discussed here several times before) there may be reduced lifespans and there can be malformations.
Someone recently provided the Ferret-genetics list with a list of the problems that can be seen with those long heaired ones but for the life of me I can't recall the name of it so I can't find them in my files. Arrgghhh. Remind me, please, and I'll look it up. I recall that there were skull malformations mentioned as part of what can go wrong with that mutation.
Acrondoplastic dwarfism has been seen with breeding for appearances in ferrets, complte with serious limb and back pain.
Those who concentrated on short faces have created ferrets who do not
have large enough dental arcades.
Breeding for pretty pelage that lacked bilateral markings on the head has resulted in at least one line (culled through sterilization) that had aortic defects.
So, I guess we do know that breeding for appearances first can have negative results, but has it impacted on lifespans in general? I don't know.
Remember, that even with excellent health care human longevity is all over the place, and although there are those who live to be around 120 most simply don't make it to that range by 40 to 50 years. Nor is that genetic variablility necessarily a bad thing healthwise. There are likely other genes carried by those who live shorter lives than the super-extreme ones which help fight off a range of illnesses or environmental assaults that may periodically arise.
What IS more of a concern, though, is when a genetic line tends to have what is below normal range (as opposed to below of longevity of the few how live to extreme ages) consistently. That is a big warning signal.