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CAT COLORS
AND BREEDS
A. Common Cat Colors
If you want
to read about which colors are commonly seen in cats, or if
you want to know what your cat's color is called, read
section A.
1.Tabbies
2.Solids and Smokes
3.Cats with white markings
4.Torties, Patched Tabbies and Calicos
5.Pointed ("Siamese") pattern
6.Frequently Asked Questions
B.
Cat Color Genetics
If you are
interested in the genetics of different colors and in what colors
are theoretically possible, read section B. Section B
is more technical. You
may want to read section A first to become familiar
with cat color
terminology.
A. COMMON CAT COLORS
This section is primarily
intended to answer the question, "What color is my cat?"
It also explains basic color terminology and gives some information about how
the colors and patterns work together. There are many colors and patterns that
are genetically possible in the cat, so this section only covers the colors that
you
are most likely to see. There are additional color mutations that are seen only
in
certain breeds; these colors are covered in the color genetics section.
Note: Cat fanciers use the term
"red" for the color that is commonly called
"orange," "marmalade," or "ginger". We also use
the term "blue" for the color
that is commonly called "gray" or "maltese."
1. Tabbies
If your cat has stripes,
it is a "tabby." (Some people call these "tiger cats.") All
tabbies have thin pencil lines on the face, expressive markings around the eyes,
and a tabby "M" on the forehead. If you look up close at the light
parts of a
tabby's coat, you will see that the individual hairs are striped with
alternating light
and dark bands, like the fur of a rabbit or a squirrel. This banding is called
"agouti." Tabby is thought to be the "wild type" (the
original color) of
domesticated cats.
There are four different
tabby patterns:
A "mackerel tabby" has narrow stripes that run in parallel down its
sides.
This is what some people refer to as a
"tiger."
A "classic tabby" cat has bold, swirling
patterns on its sides like marble
cake. This color is called "blotched tabby"
in the UK.
A "spotted tabby" has spots all over its
sides. Sometimes these are large
spots, sometimes small spots, and sometimes they appear
to be broken
mackerel stripes.
A "ticked tabby" (sometimes called
"Abyssinian tabby" or "agouti tabby")
does not have stripes or spots on its body. However,
like all tabbies, it has
tabby markings on the face and agouti hairs on the
body. This is the color
of the Abyssinian cat, but it also appears in
non-purebreds and does not
mean the cat is Abyssinian.
Tabbies come in many
different colors. You can tell what color a tabby is by
looking at the color of its stripes and its tail tip. The color of the agouti
hairs (the
"ground color") may vary tremendously from cat to cat, some cats may
have a
washed out gray ground color and others will have rich orange tones.
A "brown tabby"
has black stripes on a brownish or grayish ground color.
The black stripes may be coal black, or a little bit
brownish.
A "blue
tabby" has gray stripes
on a grayish or buff ground color. The gray
stripes may be a dark slate gray, or a lighter
blue-gray.
A "red
tabby" has orange
stripes on a cream ground color. The orange
stripes may be dark reddish orange, or light
"marmalade" orange.
A "cream
tabby" has cream stripes
on a pale cream ground color. These
stripes look sand-colored or peach-colored rather than
orange.
A "silver
tabby" has black stripes
on a white ground color. The roots of the
hairs are white. You can also have a blue silver, cream
silver, or red silver
tabby (red silver is also known as "cameo
tabby") depending on the color
of the stripes. In all cases, silver tabbies have a
pale ground color and white
roots. To make sure, part the hairs and look at the
roots.
2. Solids and Smokes
If your cat is pretty
much the same color all over, it is a "solid." Some people,
especially in the UK, use the word "self" instead of
"solid."
A "solid black" is just that: black all over. It may be coal black,
grayish
black, or brownish black. Black cats can
"rust" in the sunlight, the coat
turning a lighter brownish shade.
A "solid blue" is blue-gray all over. It may
be a dark slate gray, a medium
gray, or a pale ash gray. This color is also sometimes
called "maltese." This
is the color of the Russian Blue, Chartreux, and Korat,
but it can appear in
almost any other breed as well, and is also seen in
non-purebreds. Solid
blue does not indicate that a cat is related to any of
these breeds.
A "solid white" is white all over. Sometimes
white cats have blue eyes,
sometimes they have green or gold eyes, and sometimes
one eye is blue
and one eye is green or gold! This last color is called
"odd-eyed white."
Most solid colored cats
are the result of a recessive gene that suppresses the
tabby pattern. Sometimes the tabby pattern is not totally suppressed, so you
might see indistinct "shadow" tabby markings in certain lights even on
a solid
black cat. If you look at a black leopard in a zoo, you might also see these
shadow markings, because the black leopard has a similar spot-suppressing
gene!
The tabby-suppressing
gene is not effective on red or cream cats, so you won't
see red or cream cats without tabby markings.
Solid white cats are the
result of a different gene that suppresses color
completely. Young white cats often have vague smudges of color on the top of
the head where the color is not completely suppressed. Sometimes this persists
even in an older white cat.
If your cat is pretty
much solid black or gray, but the roots of the hairs are
distinctly white, it is a "smoke." (It's normal for the roots on a
solid cat to be
grayish; true smokes, on the other hand, have definite white roots.) Smokes
are the solid version of silver tabbies. These cats are very dramatic because
when they move, the hair parts and the white undercoat can be seen.
A "black smoke" is a solid black cat with white roots.
A "blue smoke" is a solid blue (gray) cat
with white roots.
3. Cats with white
markings
Clearly delineated white
markings (as opposed to shaded points, like the
Siamese) can appear on any color. Just add "and white" to the cat's
basic color
to describe the cat. So for example your cat might be a "black and
white" or a
"cream tabby and white."
Cats with white markings
might have larger or smaller areas of white. If you
want to describe your cat's color more precisely, there are different names for
the different amounts of white:
A "mitted" cat just has white paws.
A cat with a white spot on its chest has a
"locket."
A cat with one or more little white belly spots has
"buttons."
A "bi-color" is about half white.
A "harlequin" is mostly white with several
large patches of color.
A "van" is almost all white with color
patches only on the head and tail.
There are a couple of
affectionate, informal terms used for black and white cats:
A "tuxedo cat" is a black and white cat with white paws, chest, and
belly. It
might have some white on the face as well.
Some people call black and white cats "jellicle
cats" (after T.S.Eliot)
4. Torties, patched
tabbies, and calicos
If your cat is randomly
patched with different colors, you probably have a tortie,
patched tabby, or calico.
For cats without white
markings:
A "tortoiseshell"
or "tortie" is
randomly patched all over with red, black,
and cream. The patches may be very mingled, or they may
be more
distinct.
A "blue-cream"
(also called "blue tortie" or or "dilute tortie")
is randomly
patched all over with blue and cream. This is a soft,
pastel color.
A "brown
patched tabby" looks
almost like autumn leaves, with patches of
brown tabby and patches of red tabby. This color is
also known as "torbie"
because it is a tabby tortie.
A "blue
patched tabby" is a soft
color with patches of blue tabby and
patches of cream tabby.
There is special
terminology for tortoiseshells with white markings, depending on
how much white they have:
A "tortoiseshell and
white" or
"blue-cream and white" has only small white
areas. The body has mingled colors.
A "calico"
has more white. As a rule, the more white there is on the cat,
the larger and more distinct the red and black patches
will be. You'll notice
that the large black patches are solid black, and the
large red patches are
actually red tabby.
A "dilute
calico" has the same
amount of white as a calico, but instead of
red and black patches, it has blue and cream patches.
The blue patches are
solid blue, and the cream patches are cream tabby.
A "patched
tabby and white" or
"torbie and white"
may have any amount
of white. A patched tabby with a lot of white, like a
calico, has large distinct
patches of color, and is sometimes called a
"patterned calico," "calico
tabby," or "caliby."
5. Pointed
("Siamese") pattern
If your cat has dark
"points" (face, paws, and tail) shading to a much lighter
color on the body, it is a "pointed" cat. This is the pattern of the
Siamese cat,
but many other breeds as well as non-purebreds also come in this pattern, so it
does not mean that the cat is a Siamese. This pattern is also sometimes called
the "colorpoint" pattern (not to be confused with the Colorpoint
Shorthair
breed) or the "himalayan" pattern (not to be confused with the
Himalayan
breed).
Pointed cats are born
white and gradually darken with age. A young pointed cat
will have a much lighter body color than an older pointed cat.
Pointed cats can come in
many different colors:
A "seal point"
has dark brown points and a body color anywhere between
light brown and ivory.
A "blue
point" has gray points
and a light gray or beige body.
A "lynx
point" has tabby points!
It might have any of the colors described in
the tabby section. For example, you could have a
"blue lynx point" or "red
lynx point." The body color may show some shadow
tabby markings,
especially as the cat gets older.
A "tortie
point" has tortoiseshell
points, and a "blue-cream
point" has
blue-cream points. Patched tabby points are also
possible.
You can even have a
pointed cat with white markings! If the cat has a lot of
white, however, it can be hard to see the pointed pattern (especially on the
feet). White markings will cover up any other color where they appear.
6. Frequently Asked
Questions
Are tortoiseshell cats
always female?
Tortoiseshell
and related colors (blue-cream, patched tabby, calico etc.)
are the result of a sex-linked gene and require two X
chromosomes to
appear. Generally speaking, these colors will only
appear in females. Very
rarely, these colors may appear in male cats, but these
males are
genetically abnormal (they have XXY instead of the
normal XY) and are
almost always infertile.
What eye colors are
possible?
Eye
color is genetically related to coat color.
Pointed cats always have
blue eyes.
White cats, and cats with
a lot of white markings, can have:
blue eyes
green, gold, or copper eyes
or "odd-eyes" (one blue eye and one green or gold eye)!
Other cats can only have
green, gold, or copper eyes, not blue eyes.
The most common eye
colors are in the middle of the eye color
spectrum (greenish-yellow
to gold). The colors at the ends of the eye
color spectrum (deep
green or brilliant copper) are usually seen only
in purebreds who have
been selectively bred for extreme eye color,
but they may sometimes
appear in non-purebreds.
Are white cats always
deaf?
No. Some white cats are deaf, and some are not. If a white cat has blue
eyes, it is 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.
B. CAT COLOR GENETICS
Domestic cats exhibit a
rich variety of coat patterns and colors. The names given to these
colors and patterns are increasingly based on genetic theory. Many people have
expressed
confusion over the names that cat fanciers apply to the coat colors and
patterns, so this
article has been written to help explain the names given to the possible colors
and patterns,
and why these names are applied.
This article attempts to
introduce and describe the colors and patterns of domestic cats and
the names that are given to them. It does not attempt to explain the mechanisms
of
inheritance nor the formulas
for calculating the possible outcomes of particular breedings.
1. Pigmentation
The colors in hair, skin,
and eyes are caused by the presence of melanin. Melanin is deposited
in the hair shafts in the form of microscopic granules which vary in shape,
size, and
arrangement, giving a variety of colors.
There are two chemically
different kinds of melanin: eumelanin and phaeomelanin. Eumelanin
granules are thought to be spherical in shape and absorb almost all light,
giving black
pigmentation. Phaeomelanin granules are thought to be elongated
"footballs" in shape, and
reflect light in the red-orange-yellow range.
Several genes can cause
variation in the density of the the melanin granules, so other colors
can be produced. The most variation is found in the black-based (eumelanistic)
colors. :
Mutations of the gene for
Black give rise to Chocolate and Cinnamon. These colors are
thought to be due to a smaller number of eumelanin granules in the hair shaft.
The Chocolate
color is a medium to dark brown color; it is sometimes called chestnut. Cinnamon
is a
terra-cotta or burnt sienna color. These are alleles at the (B) locus; Chocolate
is recessive to
Black, and Cinnamon is recessive to Chocolate.
A mutation of the gene
for Dense coloration produces Blue, Lilac, and Fawn. These colors are
due to clustering of the particles of pigment in the hair shaft. This is called
dilution or
Maltesing. Blue is the dilute form of Black; it is commonly seen as various
shades of gray.
Lilac is the dilute form of Chocolate; it is described as dove or light taupe
gray, and is
sometimes called frost or lavender. Fawn is the dilute form of Cinnamon; it is
described as
"coffee and cream" or caramel color. Dilution is a mutation at the (D)
locus; dilution is
recessive to dense coloration.
In comparison, the
red-based (phaeomelanistic) colors have much less variation. Red is
usually described as orange or "marmalade", but some red cats have
rather pale
pigmentation and so people may describe them as yellow. Cream is the dilute form
of Red,
and is described as a buff color. The symbol for the gene for Red/Cream is (O);
Black is
recessive to Red.
The Red gene (O) is
carried on the X chromosome; for this reason it is sex-linked. Males
normally only have one X chromosome and so if a male carries the Red gene at
all, he will be
Red. Females have two X chromosomes; if both X chromosomes carry the Red gene,
then
the cat will be Red. However, many females carry the Red gene on only one
chromosome,
which allows the black-based pigmentation to show through in patches. This
combination of
red and black is called Tortoiseshell.
A typical Tortoiseshell
is a patchwork of black and orange, usually in a random pattern. Some
"Torties" have large patches of orange, others are mostly black. The
Tortoiseshell can be
modified by dilution, which gives a patchwork of blue and cream rather than
black and
orange. Such dilute Torties are usually called Blue-Cream. Finally, the black
patches of a
Tortie may actually be any of the black-based colors, so you may see a Chocolate
Tortie or a
Cinnamon Tortie, and, if dilution is also present, a Chocolate-Cream Tortie or a
Fawn-Cream
Tortie.
The mutations described
above have been seen and described in cats in Europe and and the
Western Hemisphere for hundreds of years. Another set of mutations of color has
been
introduced with the Siamese and Burmese cats from Asia. The Burmese carries the
gene for
Sepia color (cb) and the Siamese carries the gene for Pointed color (cs). These
are alleles at
the albino (C) locus; when they are combined (cb/cs), as in the Tonkinese,
"mink" colors are
produced.
2. White Cats
White fur is the absence
of any pigmentation. A solid white coat may be caused by any of
three genetic mechanisms, which are completely different:
Albino
white. This is recessive, and
has been mentioned in the previous section.
Complete white spotting. The white spotting factor (S)
is an incomplete dominant, which
is affected by polygenetic modifiers and usually
results in a cat that is only partially
white. However, it can be so complete that it results
in a completely white coat. White
spotting will be discussed in a later section.
Dominant white. This mutation overrides all other genes
for pigmentation, and produces
a white coat and blue eyes. As its name implies, this
is the effect of a dominant gene
(W).
In the dominant
white, the other genes for
color and pattern are still present, but they are
completely hidden. The only way to determine the underlying genotype is by test
matings
with colored cats of (reasonably) well-known genotype.
Breeding two dominant
whites will mostly produce solid white kittens, but if both of the
parents are heterozygous (W/w), then the underlying colors may appear on a few
of the
kittens. Unless the genotypes of the whites are known from pedigree or test
breeding, the
results are unpredictable.
Dominant white is found
in mixed-breed cats, of course, and notably in Persian and Oriental
Shorthair breeding programs. At one time the dominant white Oriental Shorthair
was
considered a separate breed by some associations, called the Foreign White. The
dominant
white can produce much deeper blue eye color than the albino, so it is
considered desirable. It
is believed that the best blue eyes in solid white Oriental Shorthairs are those
that are
masking Chocolate.
Deafness in white cats is
associated with the white spotting factor (S), but not with the
dominant white (W) or the albino white (c/c or ca/ca).
3. Ticking and Tabby
Patterns
All of the foregoing
discussion has described solid colors. However, the solid or "self"
colored
cat is not the most common. More cats have ticked fur than solid color, and in
most of them,
the ticked fur alternates with the solid color in some sort of pattern, which is
called tabbying.
First, ticking is the
result of the agouti gene (A) which causes the individual hairs to have
bands of light and heavy pigmentation. The agouti gene allows full pigmentation
when the
hair starts to grow, then slows down the synthesis of pigment for a while, and
then turns it
on for a while. As the hair approaches its normal length and stops growing,
pigment
synthesis stops. The result is a hair shaft that has dense pigment at the tip,
then a band of
yellow to orange, then a band of dense pigment, fading to yellow to orange at
the root.
The agouti band can be
seen in both the eumelanistic (black-based) and phaeomelanistic
(red-based) colors. In both cases, the agouti band marks the period where the
production of
melanin has slowed down. It is fairly well accepted that the color in the agouti
band of a
eumelanistically-pigmented hair shaft is still eumelanin, not phaeomelanin, but
it is the fact
that the granules are sparse and "shredded" that gives them the yellow
to orange color. The
agouti band is not an alternation of eumelanin production with phaeomelanin
production in
the same hair shaft.
In eumelanistically-pigmented
hair shafts, the agouti band is normally a drab yellow-beige
color. However, the color of the agouti band can be a richer orange due to the
effect of
"rufousing" factors. These are polygenetic factors that have not been
isolated and identified,
but breeders have been able to select for them to produce "warm"
background colors in the
tabbies. In particular, the Brown Tabby patterns are genetically Black, but the
selection of
individuals with strong rufousing has produced a rich brown color in the ticked
hairs.
The mutation
that causes solid color is called non-agouti (a/a), and is recessive.
The effect of
non-agouti is to suppress the ticking, so the same density of pigment is found
all along the
hair shaft, except at the root, where it normally begins to fade in any case.
The tabby pattern is
determined by the tabby gene (T), which causes the ticked hairs to
alternate with stripes, blotches, or spots of hairs of solid color. The
commonly-recognized
types of tabby patterns have been given descriptive names:
Mackerel
Tabby. Ticked hairs alternate
with solid hairs in stripes, as on a tiger. This is
the most common tabby pattern.
Classic
Tabby. Ticked hairs alternate
with solid hairs in a blotched pattern, often with a
circular "bullseye" on the side, or a
"butterfly" on the back. This is called a Blotched
Tabby in the UK.
Ticked
Tabby. Ticked hairs are found
uniformly over the entire coat, giving a flecked or
freckled appearance. This pattern is sometimes called
the Agouti Tabby or Abyssinian
Tabby.
Spotted
Tabby. Ticked hairs alternate
with spots or rosettes of solid color, as on a
leopard or jaguar.
The classic tabby pattern
(tb) is recessive to the mackerel tabby pattern (T). The Abyssinian
pattern (Ta) is dominant to the mackerel tabby pattern (T).
The agouti and tabbying
genes also apply to all the colors generated by the albino series
(sepia, mink, and pointed colors), but space does not permit them to be listed
here.
Associations in the US only recognize Burmese and Tonkinese in non-agouti,
eumelanistic
colors, so no tabby patterns should be visible in those breeds. The Singapura is
recognized
only in the Sable Agouti Tabby color (seal sepia ticked tabby). Tabby patterns
have been
accepted by some associations in Siamese, and they are called "Lynx
Point".
Note that there are no
true solid Red or Cream colors. Breeders have produced Red and
Cream cats that appear solid by selecting for rufousing polygenes that tend to
"wash out"
the contrast in the tabby pattern. A tell-tale 'M' can still be seen on the
forehead of most
"solid" reds.
The Ticked Tabby colors
are given different names when applied to Abyssinians and Somalis.
These are:
Ruddy Abyssinian = Brown Ticked Tabby
Blue Abyssinian = Blue Ticked Tabby
Sorrel Abyssinian = Cinnamon Ticked Tabby
Fawn Abyssinian = Fawn Ticked Tabby
The Sorrel Abyssinian is
sometimes called a "red" Aby, but this is a misnomer. These are all
black-based colors. True Red and Cream Abyssinians and Somalis are not accepted
by the US
associations.
Note that the spotted
tabby pattern is not shown as a separate genotype on the above
chart. It has not been conclusively proven whether the spotted tabby pattern is
another
distinct mutation of the tabby gene or is simply an effect of polygenetic
modifiers on the
mackerel tabby pattern. Some breeders point to the existance of spotted patterns
in various
wild cat species as support for the theory that the spotted pattern is a
distinct mutation. In
practice, however, the spotted breeds continue to produce a range of patterns
from mackerel
through spotted, and breeders must continually select for well-defined spots or
mackerel
tabbies will result.
Although they are not
shown on the chart, Tortoiseshell cats can also have tabby patterns.
In a tortoiseshell tabby, or "torbie", the same tabby pattern is
applied to both the red
patches and the black patches. The bands of solid and ticked fur in the red
patches are
continuous with the bands of solid and ticked fur in the black patches.
4. Shading
In the typical tabby, the
ticked hairs have bands of lighter pigmentation, but they are not
devoid of color. Typically, the lighter bands are a drab beige-yellow color, but
rufousing can
make them closer to orange.
At the other extreme,
shading causes the agouti band to be lighter in color. Shading can also
cause the agouti band to be wider, so that the light color extends all the way
to the root. The
effect is to produce a hair shaft that has a colored tip, in whatever color is
determined by the
color genes, and then much lighter below the tip. When the light colored portion
of the hair
shaft is near-white, it is called Silver, when it is yellow or a warm cream
color, it is called
Golden.
Several genetic theories
have been proposed to explain the inheritance of shaded coloration.
The earliest theory proposed a Chinchilla gene (Ch) which was thought to be an
allele at the
albino locus. If correct, this would imply that shaded sepia, mink, and pointed
colors were
impossible. Breeding experiments have disproved that theory. A more recent
theory
proposed another single dominant gene, called the inhibitor gene (I), but this
theory was
inadequate to explain the variations of shading and did not correlate with the
experiences of
breeders, so current theories propose at least two genes. None of the current
theories have
been experimentally proven, however.
All of these theories
seek to explain the genetic factors that apparently suppress the
synthesis of pigment after a certain point in the growth of the hair shaft. This
effect interacts
with the agouti and tabby patterns to produce varying degrees of shading, which
are
commonly called "Chinchilla", "Shaded Silver", "Silver
Tabby", and "Smoke".
In the Chinchilla, all of
the hairs are tipped with color, and then light-colored below the tip.
Since both the ticked and the solid hairs turn light-colored before the point
where the agouti
band would begin, so the tabby pattern is not visible. The tipping is so light
that the coat
looks white at a first glance, but sparkles with color on closer inspection.
In the Shaded Silver, all
of the hairs are tipped with color at about the point where the agouti
band would normally begin. As in the Chinchilla, both the ticked and the solid
hairs turn
light-colored before the point where the agouti band would begin, so the tabby
pattern is not
visible. However in the Shaded Silver, the colored tips are long enough that the
normal color
is clearly visible, particularly along the head and spine.
In the Silver Tabby, the
ticked hairs are tipped with color and then light-colored below the tip,
but the solid hairs have normal coloration. The tabby pattern is actually
enhanced by the
greater contrast between the almost-white ticked hairs and the full color of the
solid hairs.
The Smoke pattern results
from the action of shading on a solid (non-agouti) coat. All of the
hairs have full color well beyond the point at which the agouti band would
appear, and then
turn into a near-white undercoat. Such a coat looks like a solid color until you
blow on it or
the cat's movement reveals the contrasting white undercoat.
The same range of
shadings can be seen with the Golden undercoat. These are called "Golden
Chinchilla", "Shaded Golden", "Golden Tabby", and
"Golden Smoke". Rather than the
near-white of the Silvers, these have an undercoat that is described as warm
cream or
apricot.
The shaded patterns are
most striking on the eumelanistic colors, because of the contrast,
but they can also be applied to Red and Cream. These colors are sometimes called
"cameos",
but the names for the cameo colors can be equated to names commonly used for
shaded
eumelanistic colors:
Shell Cameo = Red Chinchilla
Shaded Cameo = Red Shaded Silver
Cameo Tabby = Red Silver Tabby
Smoke Cameo = Red Smoke
Since shading can be
applied to both black-based and red-based colors, naturally it can be
applied to tortoiseshell, dilute tortoiseshell, torbie, and dilute torbie.
In theory, Golden
undercoats can be applied to the red-based colors, but it is debatable
whether breeders will find that combination worthwhile. The lack of contrast in
a Red Shaded
Golden would make the effect of shading almost impossible to see. However,
Golden can be
seen in the undercoats of the black patches of a Tortoiseshell Shaded Golden or
a
Tortoiseshell Golden Chinchilla.
5. White Spotting
White spotting is a very
common mutation that causes patches of white in what is called a
"piebald" pattern. The range of variation is quite remarkable: from
white toes, to white feet;
a white streak on the nose or a white chin, to a white bib; a white belly and
legs, to white
over most of the body, leaving only a few patches of color; or even a completely
white coat.
White spotting can be
thought of as a mask over the color that the cat naturally carries.
People who have cats with just small patches of tabby markings on the head and
tail and
white everywhere else tend to think of them as white cats, but they are really
tabbies all
over. The tabby pattern is simply hidden by the white spotting.
White spotting can occur
in combination with any of the colors and patterns already
described. The customary way of describing the pattern is to add "and
White" to the name of
the color and pattern of the cat. Thus, a "Red Mackerel Tabby" would
become a "Red
Mackerel Tabby and White" and a "Lilac" would become a
"Lilac and White".
The "Tortoiseshell
and White" is given a special name (in the US); it is called
"Calico".
Consequently, a "Blue-Cream and White" is sometimes called a
"Dilute Calico".
The white spotting factor
(S) is a dominant mutation with variable expression. Cats that are
homozygous (S/S) tend to have more white area than cats that are heterozygous
(S/s) for
white spotting, but there are other modifying genes that can affect the degree
of white
spotting. Non-genetic variations have been noted. Some people have observed that
the
white area may increase as the cat gets older.
The white spotting factor
can create blue-eyed or odd-eyed cats, if it reaches one or both
eyes. The white spotting factor is associated with deafness, if the white areas
reach the ears.
Since it usually covers the eyes if it covers the ears, the deaf cats caused by
white spotting
frequently have blue eyes (but not always). The deafness may affect one or both
ears. It is
caused by a degeneration of the cochlea (inner ear) which begins a few days
after birth. The
deafness is irreversible.
Note that white spotting
can be present on a cat that is also a dominant white. Of course,
white spotting on white is invisible.
the preceding
information was obtained from newsgroups: alt.rec.cats
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