Categories: bimetallic

Bimetallic Cats

Photo via Messybeat.com. Thank you and thanks as well to Lesley Morgan.

The description bimetallic cats refers to a unique coat coloration. Bimetallic cats are flesh and blood not metal. The term currently relates mainly to Siberian cats, which are a pedigree cat that looks like a Maine Coon or Norwegian Forest Cat. All three may have the same ancestors. However, I think there are lots of random bred cats that are also bimetallic. At least they look it. Perhaps there has been little focus on moggies or perhaps I am wrong and Sarah Hartwell will scold me for writing that ;).

I am informed by Sarah Hartwell (thanks Sarah) that within some SIberian cat breeding programmes (lines) cats are popping up that have a golden-like “stain” of colour that appears to be laid over the existing tabby coat. When the tabby is a silver tabby, the effect is silver contrasted with gold, hence bimetallic Siberian cats. “Bimetallic” means two metals.

On certain occasions when the coat is suitable, adding golden blobs of colour can make the cat look like a tortoiseshell cat. Because tortoiseshell cats are almost always female, when a lot of male tortoiseshells turned up someone scratched their heads and asked questions.

It has now been decided that the bimetallic coat is due to a genetic mutation that was perhaps introduced into Siberian cat lines by a random bred (freeborn) foundation cat with which the pedigree cats were outcrossed perhaps to avoid inbreeding while improving the cat’s appearance.

What I mean by a “random bred foundation cat” is that all Siberian cats, Maine Coon cats and Norwegian Forest Cats are refined versions of the natural and original random bred cat (the moggie foundation cat) from Northeastern Europe and Russia (I suppose).

Within the current population of original Siberian cats there appears to be mutated gene that found its way to the cat fancy in America. I am not sure if the gene is recessive or dominant. I don’t think the experts know for sure but it seems to be a recessive gene brought out through line breeding. Recessive genes are often hidden and have no effect on the cat.

Here is photo of Lexus, a bi-metal Siberian cat of 11 weeks of age, from Facebook:

Bimetallic Siberian Kitten

Below is a photo of a random bred tabby cat on Flickr. It looks to me like he is a bimetallic cat but no doubt there is some reason why he is not. Perhaps this is an example of rufinism, which is described as “the degree of expression of orange/yellow pigment”³.

Bimetallic cat?

With respect to bimetallic cats, the genetic effect called “rufism” (also called “rufinism”) has been ruled out because of the “degree and intensity” of the colour¹.

At the level of each hair strand the golden colour is due to a broader band of phaeomelanin which is yellow/red/orange pigment in the hair strands. Melanin (eumelanin) is dark brown and the other banded pigment. This how a classic tabby hair strand might appear:

Tabby Hair Srand

If the phaeomelanin band is wider the hair will look more orange/yellow hence the golden colour of these bimetallic cats.

Refs:  (1) Messybeast.com (2) Original photo of tabby random bred cat on Flickr (3) Robinson’s Genetics 4th edition.

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Michael Broad

Hi, I'm a 71-year-old retired solicitor (attorney in the US). Before qualifying I worked in many jobs including professional photography. I have a girlfriend, Michelle. I love nature, cats and all animals. I am concerned about their welfare.

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  • Right of course. Thank you for your useful response! Don't worry I didn't exactly expect him to be purebred. Infact he's my first adopted cat and I just think he is so pretty :).
    Interestingly in India we do have many purebreed owners but the cats are generally flown in. Then we tend to give kittens up for adoption if we have any. No formal network of breed maintanence so to speak. Although there are a few persian breeders (and a few other popular breeds).

    • Thanks for your response. India is becoming more Westernised with respect to ownership of purebred cats and cat shows etc.. But as yet it seems that there is no registration process for pedigree cats. Ragnar is very attractive and as I said has a purebred appearance in terms of quality but how purebred and what breed is in question.

  • Wow Tamara your cat looks so much like my 3 month old Ragnar! Exactly the same markings and a yellow/ apricot tinge appearing on the white.

    The funny thing is that I've adopted him from someone and my vet is certain that he is a Wegie. I've been hoping for another opinion?

    I live in Mumbai and I do know of people who own Siberians but Wegies would be very rare here. He also has a distinctly woolly coat that is kind of frizzy at the tail and underneath. Very warm and plush but not glossy.

    • Hi Khizra, thanks for posting the photos of your super looking cat. Is he named after the Ragnar in the Vikings series?! If so great.

      In the West the only way a person can say a cat is purebred and a member of a cat breed is if they are registered and the pedigree is recorded. I know that does not happen in India.

      On the criteria of the West, Ragnar is not a Norwegian Forest Cat (Wegie) or a Siberian. But that said there may some DNA in there which could support the claim that he is one of those breeds or is part purebred or even wholly purebred.

      I have to say that on appearance I'd say that he is not an NFC or Siberian. But it is possible.

      As for bimetallic, this is a rare coat type and the concept of bimetallic is currently in discussion. I think you'll find that some people don't agree that it even exists.

      There is certainly some faint gold coloration on his undersides but I am not sure if this is bimetallic. I suspect it is not to be honest.

      Sorry I can't be more positive. However, he is a gorgeous cat. So nice looking, in fact, that he could be purebred.

  • I am posting this on behalf of Nina:

    I suppose this is a bimetallic housecat, she is blue tabby, on her back she is silver shaded (2/3 of her fur are white, tips are blue/blues striped) an her belly is golden shaded. We don't know who were her parents, in shelter they said her mother was "whiskas-like" housecat and father was probably british shorthair.

  • Thanks. Yes, your edit actually looks a little more like him. Here is his belly from about two months ago. His coloring was more silver when he was even younger.

    He's much much longer now, and weighs almost eight pounds at five and a half months.

    • Nice photo Tamara. All fur and fluff with little patches of gold. Sarah Hartwell is the only person I know who could adjudicate on whether he is bimetallic. She is the expert. Bimetallic cats are a new discovery so there will only be a few people who know much about them. Thanks for the second photo.

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