St. Ann Spay Day

Look what we caught! An extremely rare male calico!! This guy came in as a TNR and will be released back to his colony. Despite the fact that he is most likely sterile, our clinic team did neuter him - and enjoyed taking many pictures of this unique guy!

While 99.9% of calicos are female, male calicos do occur in extremely rare cases (roughly 1 in 3,000). This happens due to a rare genetic anomaly called Klinefelter syndrome, where the male is born with an extra X chromosome (XXY). Because of this chromosomal abnormality, these rare male cats are almost always sterile and cannot reproduce.

The gene for orange fur in cats is carried on the X chromosome, which is why it’s linked to s*x.

How it works:
Male cats: XY
Female cats: XX

Because the orange gene sits on the X chromosome:
Male cats (XY)
Only have one X, so they can be:
Orange or black

They cannot normally be tortoiseshell or calico, because that requires two X chromosomes with different colours.

Female cats (XX)
Have two X chromosomes, so they can be:
Black
Orange
Tortoiseshell or calico (one X with orange, one X with black)

That’s why:

🧡 Most orange cats are male
🐢 Most tortoiseshell and calico cats are female

Small exception:
Very rarely, a male cat can be tortoiseshell or calico if he has an extra chromosome (XXY), similar to a condition called Klinefelter syndrome in humans. These males are usually sterile.

Picture - credit of The Brain Maze

🎄 This Christmas, please avoid adding rawhide dog chews to your gifts!
Rawhide is a serious choking hazard and is often processed using toxic chemicals. It doesn’t digest well, can swell once swallowed, and may cause choking or dangerous blockages.
There are far safer, natural alternatives available.
Your dog’s safety is the best gift you can give! 🐶🩷

The truth