Tortoise Shell Cat Information

"Tortoise shell" refers to the coloring of a cat's coat, not its breed. According to the Cat Fancier's Association, cats of many recognized breeds can have tortoise shell markings made up of a combination of three colors that can include red, orange, brown, black, blue and sometimes white. Some of those breeds include the Manx, the American shorthair and the Persian. In fact, the CFA has a Parti-Color Division within many of their breed divisions, acknowledgement of the unique beauty of the tortoise shell and other multicolored felines.

Many people use the terms "calico" and "tortoise shell" interchangeably. There is a recognized difference between the two colorings, however. Calico cats have a sizeable amount of white interspersed with the two other distinct colors. Calicos also have very distinct patches of color, just like a patchwork quilt in which the definition between the colors is clear and noticeable. With tortoise shells, though, the three colors merge together without forming a well-defined pattern. A tortoise shell cat may have some white fur interspersed throughout its coat, but patches of color aren't distinct.

Torbies are another type of tricolored cat. Like the calico and the tortoise shell, the torbie has a mixture of three different colors, but the tabby pattern is very distinct on the red, orange or blue patches. If a cat has patches of color and has distinct tabby patterning on the red or blue sections, then she isn't a true Torbie. Torbies are clearly patterned on all colored sections of their fur.

You may have heard the myth that all tortoise shell and calico cats are female. The truth lies in genetics. Only certain chromosomes produce the anomaly that will give a cat the tortoise shell look to its coat. To put it as simply as possible, male cats typically do not have the female chromosomes that also carry the gene that will make them tortoise shell. In her article for Fanciers, cat breeder Barbara French explains that only 1 in 3,000 tricolored cats are males due to a genetic misfire. These calico or tortoise shell males are almost always infertile due to the extra chromosome they possess that gives them their coloring.