My fiance is a vet and I asked him about it. He said male calicos are genetic brainfarts and do tend to have severe health issues ranging from kidney malfunction, brain damage, hyperthyroid (which sometimes causes aggression) bone weakness, genital deformities, cancer, chest deformities, diabetes. Basically they're not supposed to exist and nature takes lengths to keep it that way. He also said they are almost always infertile (but still should be neutered if you try to keep it as a pet, otherwise it has a 70-80 percent chance of testicle cancer and will urine mark all over house and have aggressive tendencies) and rarely live past 6 months of age. None make it past 2-3 years and despite popular urban myth they are not worth any money. In fact anyone who knows the truth about male calicos won't even adopt one for free because they're short lived and often cost a lot in vet bills.
I know people who have male calicos and they can get old like any other cat, but the chance of health problems are greater in one, and they are sterile (in most cases). So some do die young, but that can happen with any living creature, not just because it's calico.
Your calico cat has just as much of a chance at a normal life as it's siblings except for mabye being sterile.
>Relax, his lifespan will be the same as any other cat, he's just very unique so be sure you find him a good owner!<
Er, not so likely according to the veterinarian I live with. He said a little more than half will pass away in the first year. But it's always possible for them to live to 18-20 like some cats can do, too. But lifespan can vary depending on what the owner is willing to spend on vet care, aka if he's diabetic or needs monthly fluid treatment to boost his kidneys. Or who knows, he could have no problems at all.
Just be sure his new owner (if you adopt him out) knows about the possible health risks and shortened lifespan before they take him home. (and that the myth about male cali's being worth money is just that, a myth and that they're 98 percent sterile.)
He just told me to tell you to double-check VERY closely because every time a client has brought him a supposed male calico it either turned out to be a mis-labled female or not really a calico and the same goes for his vet colleagues. They're just THAT rare - so rare that they 'don't really exist, from a numbers standpoint.' It's all because a cat must have two X chromosomes to be a calico and two X chromosomes = female. A male calico is x-x-y and is thus either an abnormal gene type or intersex (AKA if it IS a male and a calico there's a good chance he has male 'parts' plus ovaries!) So he may have to be neutered AND spayed, lol!
Mudskipper I just wanted to mention certain breeds of cats are prone to serious health problems more than others, so mabye the ones the vet saw were of a different breed other than domestic shorthair, so the health issues were most likely NOT because it was calico, but increased because of the cats breed.