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Some Fun Facts about Animal Genetics offered by Mitchell Veterinary Services

By February 6, 2014 February 13th, 2018 Uncategorized


1)    Are tortoiseshell cats always female?

 Yes.  Tortoiseshell and calico cats are the result of a sex-linked gene and require two X chromosomes to appear. Generally, these colour patterns will only be seen in females.  Very rarely, these colour patterns may be seen in male cats, but these males are genetically abnormal and are almost always infertile.

Lil Thalheimer Snickers 6233sni062813

2)     Are white cats always deaf?

No.  Some white cats are deaf and some are not.  When a white cat has blue eyes, it’s more likely to be deaf than a white cat with gold or green eyes.  Deaf cats make perfectly good house pets, although they should not be allowed outside because they can’t hear cars coming.


Daphne has green eyes, so she can hear, but like many cats, sometimes chooses not too!

3)  Siamese cats, Himalayans and Ragdolls (cats with “points”), are born white and gradually darken with age.  A young pointed cat will have a much lighter body colour than an older pointed cat.

 KateHickmott Meisha 6154mei013013

4)   Dalmatians are also born white and gradually develop dark spots with age. 

5)   What is a free-martin?

A free-martin is a female calf that grew in the uterus with a male twin.  The twins exchange genetic material with each other through their placentas.  As a result, the female calf has some male cells.  She will look normal on the outside, but her internal reproductive organs are altered and she is infertile.  This phenomenon also occurs sometimes in other mammals, including sheep, goats and pigs.