How can I ensure a ferret's longevity?

I am concerned with the lifespan of ferrets. I've heard that ferrets bred from Marshall Farms don't live as long as other ferrets. Is this a true statement, and if so, how can I avoid purchasing / identify ferrets bred there?

In the event someone considers this question might be opinion-based, understand the reference to Marshall Farms is due to their position as the largest ferret breeder in the United States (Wikipedia).

According to "Are Marshall Farms ferrets less genetically favorable" (All About Ferrets), you can identify a Marshall Farms (MF) ferret by observing 2 little blue dots tattooed on its ear. The article is inconclusive regarding a genetic issue (considering potential in-breeding at Marshall Farms and whether the Farm is actually doing anything about the concern) and relates back to the basic factors of diet and care as primary for longevity.

Several comments applied to the article from visitors are negative regarding MF ferret longevity. Commenter "spunky" supplies the following information, which I am unable to fact-check:

"... Marshall Farms primary customers are not pet owners, they are research facilities. Therefore, longevity is not one of the traits they breed for. They don’t even know how long any of their animals will live because they are either donated into research or euthanized once they are too old to reproduce [...] genetics are not a priority for them."

Do note that, unless all MF ferrets are neutered / spayed before being distributed to pet owners, the potential for private in-breeding of MF ferrets may exist. As they would be produced outside of MF, the resulting members of the brood would have the same genetic disposition, but not the identifying tattoo. This might not be true for broods resulting from the pairing of MF ferrets to non-MF ferrets.

• Another factor in the health of Marshall ferrets is that Marshall spays/neuters ferrets too early. They've come under fire for the practice before because it's been linked (though not proven) to adrenal disease in ferrets. You can read more about it at this link: drsfostersmith.com/pic/article.cfm?aid=1983 That said, Marshall ferrets still need love! – Cuthbert Oct 10 '13 at 19:06

I live in Europe in a country where most of the ferrets were imported about 15 years ago and most of the current population comes from only small number of animals. I know about cases when a ferret had the same male as father, grandfather and great-grand-father.

Over the years, a lot of people tried to fix the situation by importing animals from other countries but there are still many animals which die young (2-6 years) because of various health issues.

The longevity of ferrets is most affected by genetic predisposition. Yes, care and diet will affect the longevity, but in-breeding will affect it (shorten it) much more.

To ensure the longevity of your ferret, you should first check its ancestors. How healthy are they? Do they have kidney problems? Are you sure the parents or grandparents were not related to each other?

If the vendor cannot tell you about the ancestors (or show them to you and let you pet them), don't even consider buying a ferret there.

Also note that the character of a ferret can be affected a lot during the first 3 months of its life, which is the time when the little ferret is still with the breeder. Getting a ferret from a big farm usually means getting a ferret that has not been pet at all and it's a wild animal.

I would recommend not to buy a ferret from a breeder that has more than 3 litters a year. He/she just cannot pay enough attention to every ferret and the risk of a wild ferret is too big. Don't buy from someone who actually has ferret breeding as a living.

So the answer to how can I avoid purchasing... Is just Invest the time to learn about the breeder and the parents of your ferrets.

Our ferret was a Marshall Ferret purchased at a local pet store in Springville, NY in 2012. She was born October 2011 and died July 2014. She had advanced insulinoma and adrenal disease and had to be put down due to painful "screaming" seizures. We were devastated by her very early death and discovered it was common from her breeder. She had to blue dots tattoo and I verified with her paperwork she was a Marshall Ferret. The vet tried to treat her comfortably but she became sick very quickly.

I bought 2 from marshals, came with a little certificate of birth . (Local pet shop) I made sure they had fresh food and water 24/7 ,2 hours a day play time , nice big cage , clean cage . My male lived up to 8 years , my female is still alive she is now 8 years .