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Linwood Animal Hospital

504 Linwood Drive
Paragould, AR 72450


                                                     "Vet Notes"

 Dr. Brent Reddick & Candi



April 2012

This month's question is an interesting one.  It was submitted by Richard Puckett.  Richard asks the question,  "Why are all calico cats female?"

First off, a "calico" is not a breed, but a specific color pattern.  To be called "calico" it must have three colors present in its coat: black, white, and orange.  These three colors come in several varieties and shades, so they don't all look the same.  As the question suggests, yes, calico cats are almost exclusively female.

The short and simple answer is that it's genetics.  Coat color is a sex linked trait in cats.  Just like in people there are X and Y chromosomes that determine the sex of the offspring.  Females are XX and males are XY.  Color genes are only found on the X chromosome.  Interestingly black and orange are treated (by cats) as one color.  The white color must be on a separate chromosome all together, but it still must be from an X.  So, if I haven't lost you yet, in order to possess 3 colors it requires XX chromosomes... which by default makes them a female.  I'd prefer not to venture into explaining the genetic anomaly where male calicos do exist... they're very rare.

Now, more importantly, how does a question like this teach us something we can all use?  Practically speaking, it may save you some time when you're attempting to restrain that wild neighborhood cat to see if you should schedule it for a spay or neuter.  Save your fingers and schedule the spay:)

The big take home message should be the importance that genetics plays in the health of our pets.  Nearly every breed of cat or dog has genetic predispositions to have or develop certain health conditions.  So, do your homework, and research the breed you're interested in before acquiring the pet.  This will allow you to identify potential issues ahead of time, and determine if those traits exist in the parents of the litter.  Demodectic mange, hip dysplasia, and patella luxations are just a few examples of the many genetic conditions where selective breeding can play a big role in prevention.

Thanks Richard for the excellent question!

God Bless!

Brent Reddick, DVM

If you have any question about this topic or any other veterinary related question please let me know!                                                                           




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