Ok so, one of the pups I bred from my alphas apparently died after I sold it... but it was just a pup? A one year old pup.. I just happened to look at the offspring part under wolf vitals and only two of the three offspring my wolves gave birth to were there... so i went and found the message in game mail that said it was bought and I clicked on the pup's name and for age it said it was deceased.... I thought wolves only die sometime after they turn 15?
If you sell a wolf and the pack wither free ranges it or retires it, the wolf can die no matter the age. After one day of being in the free range without heading to eh sanctuary the wolf will pass away and be qualified "deceased."