A question for those in genetics...

Hi. My question is that I've read in SEVERAL places, that if you have a white cat with blue or two-toned eyes, the chances are they will be deaf, or deaf on the same side as the blue eye in two-toned cats. If the cat has a dark mark in bewtween the ears when he/she is a kitten, it will not be afflicted by the deafness.

My question is, is this a speculation, or a proven fact?

I think it CAN be the case in some white cats with blue or two-toned eyes. Just like a calico cat is almost always a female but there can be an exception and I have also heard that many orange tabby cats are males, but that is not always true.

I guess it just depends.

Originally Posted by Jen

I think it CAN be the case in some white cats with blue or two-toned eyes. Just like a calico cat is almost always a female but there can be an exception and I have also heard that many orange tabby cats are males, but that is not always true.

I guess it just depends.

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Yeah... I have an orange tabby male, and an orange tabby female. Female is the male's daughter. So, it's not a scientific study has been done, it's just common?

I have heard that most all white cats are deaf...regardless of eye color. I had a foster group of 5 kittens that were all white and had blue and green mixed eyes. To my belief, all of them were deaf, although its not the easiest to tell when they are little. Next time I am at my vet (probably next week) I will ask how the genetics work!

I grew up with a pure white cat with blue eyes and she was deaf. I have asked many people when I notice that if their cat is pure white with blue eyes whether the cat can hear or not. From what I have determined the shade of blue in the eyes can make a difference, the paler the blue then the cat is deaf, the darker then the cat is not always deaf.

Also a good many orange tabby's tend to be males (about 75%) but not all.

Originally Posted by Petnurse2265

Also a good many orange tabby's tend to be males (about 75%) but not all.

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I thought it was 90%?

It could very well be 90% I was just giving a rough generalization. The majority of orange tabby's that come through our clininc are male.

Just looked it up... 95% are males! Man, Mirah must be pretty rare!

Wow, I knew it was high but I didn't expect that high.

But another website says that in order to get a reb tabby female, you have to have a red tabby mother and father. CJ was white. Hmmmm....

Wait a minute, that can't be right! My sister-in-law has a cat that delivered a litter of 6 kittens last year. I believe 2 of the six were red tabby females, 3 were red tabby males, and the other one was a blue. I think (I haven't seen them for a while.) The queen was/is a tortie. Very definitely not a tabby.

Yeah, and CJ is white, Billy is red tabby. Maybe I read it wrong? It was a different website than the percentage.

Kionu is white w/grey shading and really light blue eyes. Is there a certain age that they start to lose their hearing?

It is strictly pure white cats, if they have any color on their body they won't be deaf. The pure white ones are born deaf.

Right, I thought Elle was born deaf. Turns out she isn't. I thought she had blue eyes, too. The vet told me that she WILL have blue eyes. Well, one is turning orange. But I think she's unilateral. She only responds to me from one side. Her blue eye side is deaf, I think. She doesn't have the dark mark, either. That was my question, was the dark mark a scientific study, or speculation?

The dark mark is scientifically proven (though that does not mean that only pure white cats with blue eyes are deaf) it has to do with a gene and only the pure white ones carry it. Just like blue eyed dalmations are deaf too.

Thanks Petnurse! Now I can rest easy.

Originally Posted by CJandBilly

But another website says that in order to get a reb tabby female, you have to have a red tabby mother and father. CJ was white. Hmmmm....

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This is not completely true. To get a red female, you'll need to mate a red male and a red or tortie female.

White cats can be carrier of (hidden) colours if they are heterozygous white.

Here's an article about white cats and blue eyes: http://home.earthlink.net/~featherland/off/white.html

Sissel

Cool! Thanks for the article! That was very interesting!

Originally Posted by CJandBilly

Just looked it up... 95% are males! Man, Mirah must be pretty rare!

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Really? that rare? The rescue group i used to volunteer for had 4 female orange tabbies at one time, they have another one right now too. I was fostering one of them.