One of the main distinguishing features of tortoiseshell cats is that over 99.96% of torties are female. This is due to the genetics required to produce the beautiful orange coloured coats, as two X chromosomes are needed for the range of red, black, orange and autumnal colours – and male cats will only have one X and one Y chromosome.
Although this means that it is almost impossible for a male cat to inherit the tortoiseshell colours, very occasionally a male tortoiseshell is born if the cat has an extra strand of DNA and has an extra X chromosome. This means that he will have an imbalance in sex chromosomes, so he is very likely to be sterile – and this is a condition that can also occur in humans (not the tortoiseshell colours, but the extra X chromosome!)
Studies vary from 1 in 1000 to one in several thousand cats being born as a male tortoiseshell cat, and although they are so rare this does not necessarily mean they are very valuable. They will look very similar to other torties, and they cannot pass on the tortoiseshell colours.
There have been various reports in the media over the last few years regarding male torties, and we would love to hear from anyone that owns a male tortoiseshell cat or has come across one. We are sure that they bring the same amount of good fortune, love and fun to a family home as a ‘regular’ female tortie – and it would be great to know if they have the same tortitude as well!