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LMF: Genetics and the White Cat

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The Norwegian Forest Cat: a description of the breed
Roy Robinson on White Cats
The Snow Cats
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Further down on this page:
Virginia Baehrel on possible influence of red gene on deafness
1998 update: Paula to NFCFA members

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Genetics and the White Cat

by Paula Swepston ©

This article was written in July 1994. A few update comments are incorporated in this presentation.

The genetics of the white cat is a fascinating subject, better explained in all its subtleties by a scientist. However, as lover and breeder of white Norwegian Forest Cats, I'd like to offer a starter course for laymen and discuss, among other things, the problem of possible deafness in white cats of all breeds.

EC Torvmyra's Yolanda, NFO, photo: Chopard©

The color white is caused by a dominant epistatic gene symbolized by the letter W (white) which, if inherited by the cat, masks in the phenotype any other color, dominant or recessive, the cat may have in its genetic make-up. The owner may ask in puzzlement, 'Well, what color is my cat really?' When we bought Fenja, Monica Chopard explained to us about the spot of breakthrough pigment usually found on the heads of white kittens; this spot, which disappears as the cat grows older, allows one to determine the animal's underlying genetic color. In Fenja's case the spot was missing, but since her mother is a red it seemed safe to assume that Fenja herself might be tortoiseshell 'underneath', and this was confirmed over the years, as she gave cream and blue cream kittens. At the time, we were novices, and I think one of us ventured to say, 'But maybe she's an all-white cat.' Well, no is the answer. Those do exist, for instance among the Persians and Turkish Angoras, whose breeders marry whites to other whites. There it's possible to have a homozygous (WW) cat, but Fenja is definitely heterozygous (Ww), because only her father is white.

Live and learn. Time went on, I asked a lot of dumb questions, read Roy Robinson, asked more questions, and now it's no longer such a mystery. But not even the scientists agree about everything that goes on under those white exteriors! We've said that the white color is caused by the W gene, but according to a second theory, it could derive from the spotting gene (S) responsible for white paws, noses, and other decorative bits. (To the non-scientific mind this sounds like hoping your freckles will run together so you'll look sun-tanned.) Amanda Thomas, a British Maine Coon breeder researching deafness in white MCO's, believes the W gene to be a mutation of the EC Naima's U-Fenja, white Norwegian Forest cat, photo: Paula©S, or the S a mutation of the W; in any case they may be related.

As we know, some white cats are born deaf. (This is the chief reason we have not been crossing white x white among Norwegians.) Some breeders, including Ms Thomas, hope to minimize the possibility of deafness by mating their whites with colored cats having little or no white spotting. Judith Zuurveld is skeptical about this because her white male,
EC Acton Bell Felis Jubatus, who probably carries the spotting, has given a relatively low number of deaf kittens (23% as opposed to the 80% quoted by one breeder in an Atout Chat article on Turkish Angoras). Based on her experience she speculates that the S may even protect the offspring against deafness.

[Update 2002: according to the posthumously updated edition of Roy Robinson's 'Genetics for Cat Breeders', it is no longer believed that the white spotting gene bears any relevance to deafness. In an article reproduced elsewhere on the site, Mr, Robinson recommends pairing yellow-eyed hearing whites with large patches of breakthrough color, in order to collect largest possible quantity of protective polygenes. You can read this article by clicking HERE]

It is not a tragedy to have a deaf cat. In fact, as some cats (10-15% of those over 13 years old) lose their hearing with age, it's a good idea for us all to think about living with this disability. We breeders must be especially alert, so we can pick the best homes for deaf kittens and help the new owners protect and communicate with their pets. Even though, as Mr. Robinson says, it is not possible to eliminate deafness, we can hope to lower its incidence in future generations; to this end serious breeders are comparing the results of their matings, and keeping track of them in an organized way.

The initial problem, obviously, is to establish which kittens hear and which don't. Some writers simplify the issue by making it dependent on eye color. One hears over and over again that yellow-eyed cats hear, blue-eyed cats are deaf, and odd-eyed cats hear only out of the yellow-eyed side. But these are generalizations, and are not always true. For one thing, there are also white cats with green eyes, and these never seem to be mentioned at all. Then, as we know, some yellow-eyed cats are deaf, and some blue-eyed cats hear and give hearing kittens in their turn. Of the two odd-eyed kittens we have had here, both are fully hearing on both sides. Still, there may some connection. According to Fran Pennock Shaw in Cat Fancy magazine (USA, Jan.1994), humans who have Waardenburg's Syndrome, a condition involving congenital deafness, usually have a streak of white hair and blue eyes, no matter what their skin color.

Maison Forte Snowcats litter, photo: Paula©

Meanwhile, if you're raising a litter of white kittens, you won't want to wait until their eye color has changed before determining how well they hear. In a mixed litter it's easier to decide, because you can compare the whites' progress with that of their colored litter mates. With an all-white family it's more difficult. You can use all sorts of noisy tricks to check reactions: rattling keys, crinkling paper, blowing police whistles. Try to stand where the kittens can't see you when you want to surprise them. (Whether or not you succeed in establishing the kittens' hearing capacities, you'll probably convince their mother to move them all to a dark corner of the cellar!) Another trick that seems to work is hissing at them; the ones who hear will probably hiss right back. But do it away from Mama, and don't exaggerate -- they shouldn't regard you as the enemy! My favorite test is the Dies irae from Verdi's Requiem. Written to wake the dead, this music, turned on full-blast, is ideal for scaring baby kittens across the room! (Afterwards, switch to Mozart!) While they are tiny, by the way, you will only make yourself nervous by studying every little twitch of their ears. By the time our last litter was 3 1/2 weeks old I'd decided they were all either deaf or mentally retarded, when my cleaning lady came downstairs one day and said, 'Sorry, Madame, I can't do your bedroom. Your little kittens are scared of the vacuum cleaner.' She couldn't understand why I was so delighted! When they're a little older, you'll start to notice which ones respond to the sound of the refrigerator door, whether they react when you break a glass.

'Hearing' Through the Paws

‘It is interesting to observe deaf cats compensate through having to rely on other senses of sight and smell and even develop improved sensitivity to vibration via the feet. This is perhaps a crude form of replacement hearing because airborne sounds will be muted as they pass into the ground, but the cat, even if deaf, may be highly sensitive to vibrations....

As we have seen, the whole body of the cat is sensitive to vibration to some degree, but it is thought that the cat's paws are especially competent in this respect. This may help explain why cats are reported to be able to predict the imminence of certain types of earthquakes.'

from Claws and Purrs, Peter Neville©
Sidgwick & Jackson Ltd, London
ISBN 0283 06123 5

But it isn't always easy to tell, even with adult cats. This is complicated by the fact that, according to Ms Shaw, 'the majority of hearing-impaired cats are deaf only in one ear....The cats compensate so well for the partial loss that owners and veterinarians may not suspect anything.' Show judges wear their fingers out trying to get a reaction to little snapping sounds, but a calm, experienced cat of any color may be too bored or disdainful to respond. On the other hand a deaf animal may react to the movement of air beside its ear or may catch sight of the moving fingers. If a deaf cat is living in a household with more than one animal, you may not realize at first that the reason he's coming to dinner is not because you called but because he sees everybody else rushing into the kitchen.

In fact it's not a good idea for deaf cats to live alone. They tend to be sweet and dependent, purring and following their friends around, and need the companionship of humans and other animals. Judith points out that they are ideal for families with big dogs, because they aren't frightened by barking! They're not afraid of hair-dryers either, which can be a blessing as bath time approaches.

These cats respond well to visual cues, and the owner of a deaf pet should work out a system of signals for communication. I've tried it for fun with my hearing cats. They learn very quickly that a 'come here' hand gesture and finger to the lips means a special food treat away from the other cats. Establishing eye contact is important before going on to anything else. Since a deaf cat can't hear you coming it's best, to avoid surprising him, to let him see you before you pick him up or stroke him. Same thing if a reprimand is in order. Make eye contact, then put your hand in front of the cat's face and shake your finger 'no'. Some people turn the light switch on and off rapidly to signal, or stomp their feet -- don't forget, the deaf can still feel vibrations. In some cases a shot of water from a plant sprayer can be useful.

Above all it's important to protect a deaf pet. He can't hear a car coming, and this means you should never let him wander around the neighbourhood. (I feel the same way about my hearing cats, but the added danger here is obvious.) And he can't hear the hisses and growls other animals give as warnings, so, especially until a new cat has settled in with the other family pets, it's a good idea to keep an eye open on his behalf. (Similarly, if one kitten is consistently more aggressive at play than his littermates, it could be because he doesn't hear their protesting squeals.)

No breeder of pure white cats is exempt from the possibility of deaf kittens. We shouldn't be embarrassed about it, but work to keep track of our matings and repeat the ones that produce the lowest incidence of deaf offspring -- the same thing applies to other genetic faults that arise from time to time. Above all, we shouldn't hesitate to talk about the problem with other breeders or with clients. My experience has been that clients are not necessarily put off by the idea of deafness. Frank explanation opens the way to a situation of mutual trust, and prepares the new owners for what they may encounter. Many people want a white kitten whether it's deaf or not. Recently I lost a sale, because a lady absolutely wanted a blue-eyed white -- she didn't mind if it were deaf, but it had to have blue eyes and mine were all yellow-eyed.

A few adjustments may be necessary on the owner's part, but the reward can be an especially loving relationship, and a beautiful companion.

P.S. Since 1995 the use of deaf white cats for breeding and showing is no longer allowed in FIFé. No point going into the pros and cons of this decision now; it was passed, perhaps too hastily, in the hope that the incidence of deaf kittens could be reduced, and FIFé breeders must honor the new rule. All the same, I hope this article may be useful, especially to debutant breeders who may be dealing with their first litter of whites, and that it may help demonstrate that a hearing problem does not handicap a cat for life as a cherished pet.

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The following is taken from article written by a French Turkish Angora breeder named Virginia Baehrel for a newsletter called P.A.C.I.O.N.S</b>. I feel that her theories about the red gene protecting against deafness merit consideration. It interests me especially because Fenja - who as indicated above is white with blue cream underneath - has had a 100% batting average: seven white kittens in four litters, with three different fathers, have all been hearing. This is a very modest sample, but is perhaps indicative. I would be very happy to hear of other breeders' experiences!

Whiteness, Deafness, and Genetics

by Virginia Baehrel ©
December 1994

In Holland, the USA, and France we have noticed that the red gene goes a long way towards cancelling the 'deaf' specificity. The more we blend red into a kitten's pedigree, the more chance the white kitten will be born hearing perfectly. Results: in Holland, certain breeders of US [Turkish Angora] lines (Capaqua, Azima's) as well as some of us [in France], are trying to work with white on the basis of red.

Results: I have never again had any deaf kittens, except one, in spite of two homozygote mothers (not deaf) and white fathers. Why?

Simply because it seems that the cells at the origin of the nerve structures of hearing and the cells which produce melanocytes, which produce pigments such as eumelanine (black and derivatives) and phaeomelanine (red) are linked closely. The W gene appears to be an inhibitor of eumelanine but not of phaeomelanine.

Duchess & Tom

White homozygotes which do not carry colours never transmit colours, but they nevertheless bear genetic traces of these cells. This is why they sometimes have different or green eyes. Without these traces they would be born albinos with red eyes. Since the W gene inhibits the majority of eumelanines, these homozygotes with black ancestors, or which carry black, are born deaf. The blue of their eyes is, in addition, very light. White homozygotes with red grandparents are systematically born not deaf. The more we concentrate the red polygene in the ancestors, the more we concentrate phaeomelanine (in polygenes), and the more the intensity of the eye colour is important.

All crosses possible. The results:
- kittens which are not deaf
- blue eyes
- an almost total absence of deafness....

P.S. A deaf cat does not suffer at all. Of 25 kittens born between 1989 and 1994, I only had one deaf kitten. He was just as lively and healthy as his brothers. He was not rejected and he had his place in the hierarchy of the group. He was extremely alert and even more affectionate than any other 'normal' Turkish Angora.

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EXTRACT from an article in the September-October issue of the French magazine FeliMag, entitled De la naissance à trois mois: les étapes de son autonomie, ('From birth to three months: steps towards autonomy') illustrating some facets of normal development in this area. (Our translation)

Even though the auditory canals of newborns are closed, these kittens perceive sounds from the third or fourth day. As early as the day after they are born, a loud or sudden noise will provoke a jump or at least a contraction of the eyelids. An electroencephalogram shows activity in the part of the brain involved in hearing from 2 or 3 days. The hearing canal begins to open at between 6 and 14 days (9 days on average) but is only complete at 17 days. At the same time, the sense of hearing is refined and becomes completely functional at around 4 to 6 weeks. The animal begins to follow sounds (the mother's call, or the sound of your voice) during the second week of life but this orientation mechanism does not function perfectly until around the age of one month. As of the age of 3 weeks, the kitten distinguishes familiar and reassuring sounds from unusual and disturbing noises which provoke a reaction of fear or intimidation.

For further reading, try the following site of British Maine Coon breeder David Brinicombe. You may not agree with everything he says in his study of deafness and the white gene. I myself know too many hearing blue-eyed white cats to be happy with his theory that only yellow-eyed subjects should be used for breeding, and of course the idea of crossing in Foreign Whites to get blue eyes from the albino gene is absolutely unacceptable to anyone interested in keeping a breed like the Forest Cat pure and true to type. However, he has a lot of interesting things to say. Have a look for yourselves!

Jette Eva Madsen certainly needs little introduction to Forest Cat breeders around the world. Well-known FIFé judge and breeder of Norwegians, (including 5 World Winners, 2 of them white), she is an excellent source of wisdom on the subject of white Forest Cats:

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This article was written for The Skogkatt, newsletter of the Norwegian Forest Cat Fanciers' Association, USA.

White Forest Cats: 1998 Update

Dear American Wegie-lovers,

I am writing to try and give you an idea of the status of white Forest Cats over here in Europe. I know that several American breeders have imported whites for their catteries, but it seems that not everyone is certain of how the color is regarded here.

In 1994-95 there was a big brouhaha in Hessen, Germany, over white cats in general, and this led to all the problems we have had since. It was started by a pet owner who had gotten a deaf white kitten from a breeder who neglected to inform the new owner of the kitten's problem. This became a cause célèbre in Germany, and got all the animal rights folks out in force. Among other things, it became popular in Germany to say that raising white cats of any breed was tantamount to 'cruelty to animals'.

FIFé intervened rapidly with an injunction against breeding and showing of deaf cats, their haste justified by a wish to stave off a movement in the European Community to pass an international law forbidding all breeding of white cats.

The FIFé rule stipulates that deaf whites may not be used for reproduction, or presented in shows, not even in the neuter category. This rule was passed at the 1995 FIFé General Assembly. A veterinary certificate testifying to a cat's hearing abilities is required for breeding and/or showing a white. In countries where audiometric testing is possible, this more exact examination is required. (The only country I know of that offers general availability of the audiometric exam is Germany. In Switzerland one has to go to Bern, and in France the vets seem to find it altogether a foreign idea.)

The FIFé rule was not taken up by the independent associations; and at least in France one does see deaf cats being presented in independent shows.

In spite of the problems, the breeding of white cats still flourishes in Europe, especially among the Persians, and of course the Turkish Angoras. It is true that there was some backlash against Norwegians and other whites in SOME contries, but this is evening itself out as time goes on.

In Denmark and Holland, the popularity of whites seems never to have changed much. In Switzerland, according to what I observed at the time, the price of white kittens, even deaf ones sold as pets, DOUBLED in many cases, because they became rare.

In France, there were never so many breeders of white NFO's compared to the more traditional colors, but the popularity of white cats in general does not seem to have suffered with the pet-buying public. There is a long tradition in this country of beautiful white Persians, but I have sold white Norwegians to folks who, having lost an aged Persian, did not care for the more extreme look of Persians being raised today. They still wanted a white cat, though, so they turned to the Forest Cat to get big, longhaired, and white, but without the squashed-in nose. (A fashion, by the way, that does nothing at all to favor the cat's respiratory health, but which is allowed quite happily by pedigree-giving associations. I once heard a famous French Persian breeder, judging a Persian kitten, say to the skeptical audience, 'You may think this is ugly, but he is SUPPOSED to look this way. A good Persian should have NO NOSE AT ALL!' Right, and a healthy cat is SUPPOSED to have tears running down his face his whole life, and asthma attacks to boot! Let's be honest - there are other things besides deafness that can afflict feline quality of life, and many of these are not only tolerated, but even encouraged by the cat fancy!)

I'm a bit surprised that there is still doubt about the popularity of white Forest Cats over here - especially in light of the publicity given the new white World Winner, WW K98 Skakmat Felis Jubatus, owned by Martin Kristensen of Denmark! [update: Beautiful Skakmat is, in fact, the only Forest Cat to be a double World Winner; she won again, as an adult, in 2000.]There was also a white neuter nominated at the Poznan World Show: EC/EP T'Anne's Sven Jutte, bred and owned by Anne Weijman of the Netherlands. Sven has received so many honors I can't even count them, both before and after he was neutered; most recently he was declared Best All-round Forest Cat of 1997 in Holland, and he was # 1 neuter in the 1997 Skogkatt of the Year competition. Other whites featured in that list are GIC Bergansius Nehalennia, Narviks Vulcan Tuvok, and EP/EC S*Wonder's Tarquin. So much for the idea that white Forest Cats are no longer shown in Europe!

In France we had two whites on the Top Ten list for 1997. My own EP Jolly Cotton de la Maison Forte was #1 neuter, and since his photo appeared in one of the French magazines, I have received a gratifying number of requests for white kittens. It is true that most people who start out looking for a Forest Cat pet tend to want a tabby, because that is what they have seen most often at shows and in the press. But when we get calls from people who just want to come see what a Forest Cat looks like, it is usually our 2 white boys who get the most attention.

Don't know if this will be helpful or not - but I think that NFCFA members interested in importing whites may rest assured that the European breeders offering these kittens are not just trying to palm off something unwanted over here; in Europe the fashion for whites is picking up again. Other colors - notably the famous fawns and cinnamons - have been questioned by some European breeders, but from the beginning, white cats have always been a part of the Forest Cat spectrum.

Deafness is a possibility for every breed that features white cats - that is, almost every breed on the face of the earth! So what's new? We are better aware of the problem now, and it does not make white cats less beautiful or desired. White cats are a natural part of the feline community. Breeders did not create the color, and whites have survived, Lo! these many centuries, in fields, forests, and even city streets, without help from mankind.

Those of us who love and breed whites are responsible for surveying the deafness problem, but the argument remains the same: they were always there, always loved, and no amount of constraint placed on breeders is going to eliminate the white street cat! It is our duty is to assure that our white thoroughbreds develop in the healthiest way possible. We must continue to exchange unpredjudiced information, keep trying out various theories as to which matings produce fewer deaf kittens, and propose only the best, hearing subjects for reproduction.

The idea that white cats are defective in other ways, specifically because of their color, is without foundation in any serious forum that I have seen. Recently I have been receiving electronic echoes (well, you know, nothing is private online!) suggesting that the white gene is a sort of 'death gene'! In addition to the possibility of deafness, white cats are supposed to suffer from blindness as well. They are all supposed to have diarrhea, and the females are reckoned to be poor-risk mothers, having small litters and a high incidence of uterine and kitten death. White cats are supposed to lead shorter lives than others, dying at about two years of age.

Well, sounds like 'witch hunt' to me, classic rumor fabrication, based on nothing but hysteria! I have not seen specific cattery names mentioned in this connection, and would respectfully suggest that it is not necessarily the white gene which is at fault in these cases, but the line. The diarrhea may be due to nothing more sinister than poor diet or sanitary conditions; the other problems may occur in cats of any color. In my own cattery, we had reproductive problems with a silver female, and with her mother and grandmother, both black and white; all three are sterilized now. None of these cats' pedigrees has anything at all in common with my 'white line' - which is extremely healthy in every respect, and in which the females have normal-sized litters (4, 5, up to 7 kittens) born easily with no defects.

This whole issue brings to mind Jette Eva Madsen's caution (see her web site address, below) that breeders must never give in to the temptation to use a poorly-typed Forest Cat or one with heart problems, tail fault, or any other undesirable traits, just because it happens to be a hearing white!

Well, there is so much research still to be done, and we may never really be able to pin down exactly how to eliminate the problem. But of course we keep trying.

In closing, I send greetings to all of you 'over there'. One of the hardest things for me about being an American living abroad is not being able to meet you personally, visit the American shows, and see your beautiful Forest Cats up close. The magazine is a big homesickness remedy though, and I read every issue with pleasure. Keep up the good work!

19 October 1998

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Skogkatt Online: International Forest Cat links
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odd eyes
'Jeepers, creepers,
Where'd you get those peepers?
Jolly jeepers,
Where'd you get those eyes?'

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