Cavy Genetics - Basics of the Breeds
Finding good information on breed and color genetics for cavies is MUCH more difficult than rabbits. The following is a compilation of what I've managed to pull together. Additional information/sources GREATLY appreciated! Written for the reader who already knows rabbit color genetics (or has at least read my rabbit color genetics 101).
The ARBA/ACBA Standard of Perfection recognizes cavies in 13 breeds. Differences among the breeds are not as pronounced as the differences among rabbit breeds -- in many cases a single gene mutation is responsible for the distinction between the breeds. Basic genetics suggest that crossing breeds would thus result in perfectly showable animals, but doing so is not generally recommended as hybrids often results in animals with intermediate characteristics or mismarkings (such as too few rosettes).
The ARBA/ACBA Standard of Perfection recognizes cavies in 13 breeds. Differences among the breeds are not as pronounced as the differences among rabbit breeds -- in many cases a single gene mutation is responsible for the distinction between the breeds. Basic genetics suggest that crossing breeds would thus result in perfectly showable animals, but doing so is not generally recommended as hybrids often results in animals with intermediate characteristics or mismarkings (such as too few rosettes).
Coat Length - L
Short coat (as in Americans, white crested, and teddies) is a dominant trait - designated L. Long coat (as in Silkes, Peruvians, Coronet and Texel) is recessive, designated l. Hybrids - Ll - usually have short coats, but may be slightly longer than the purebred LL.
Rosettes - R
The dominant R allele causes rosettes (as in Abyssinians and Peruvians). Breeds without rosettes (American, white crested, teddy, Silkie, texel, and coronet) are rr. Modifiers genes (separate, unknown genes) are needed to get the correct number and placement of rosettes. Abyssinians should have 10 rosettes. The long-haired 'sweeps' of Peruvians are also a modified rosette - only 6 are typical.
Star - St
The dominant Star allele (St) creates a single 'rosette' in the middle of the forehead (as in white crested and coronet). Breeds without the crest or coronet have the recessive genotype (stst). Additional modifier genes are responsible for the color and shape of the star. Hybrids (Stst) will have a coronet, but it is often poorly shaped due to the loss of the modifiers.
Rex - Rx
The recessive rex allele (rx) causes a fur type similar to that of a rex or minirex rabbit. Longhaired cavies with the rxrx genotype (essentially silkies with rxrx rather than RxRx) are texels, which have long ringlets for fur. Shorthaired cavies with the rxrx genotype are called rexes - these are accepted in Britain and other countries, but not (yet) by the ACBA. Similarly, coronets with rxrx are called merinos and Peruvians with rxrx are called alpacas - none are (yet) accepted by ACBA.
Teddy - T
The recessive teddy allele (t) causes a crimping in the hairs, resulting in a plush coat that stands on end. This is a second recessive 'rexoid' gene completely separate from rex. All non-teddy breeds have the dominant T- genotype. Of note - crossing rex and teddy (TTrxrx x ttRxRx -> TtRxrs) defaults to normal coat type.
Satin - Sn
The recessive satin allele (sn) imparts a glowing satin sheen to the coat - over and above the normal luster of the healthy coat. Satins are accepted in American satin, Abyssinian satin, Silkie Satin, Peruvian satin, and Teddy satin.
Swiss (sw)
The recessive swiss gene (sw) is a third recessive rexoid gene. Swiss are swsw, Non-Swiss are Sw-. Test crosses with rex and teddy have proven this gene to be a separate locus - crosses (TtSwsw, RxrxSwsw) default to a normal coat type. Many Swiss lines apparently carry rex (swswRxrx) and swswrxrx likely exist and appear to be the Swiss-type. The Swiss gene may be directly affecting hair length as swiss generally breed true for a semilonghair type (with occassional shorthaired individuals).
Breed Genotypes
Taking American as the 'base type':
American - L-rrststT-Sn-Rx-
Abyssinian - L-R-ststT-Sn-Rx- (American plus R [rosettes] and modifiers)
White crested - L-rrSt-T-Sn-Rx- (American plus St [star, crest or coronet] and modifiers)
Teddy - L-rrststttSn-Rx- (American plus tt [teddy])
Silkie - llrrststT-Sn-Rx- (long-haired American)
Peruvian - llR-ststT-Sn-Rx- (long haired Abyssinian with reduced rosettes)
Coronet - llrrSt-T-Sn-Rx- (long-haired white-crested [except other crest colors are allowed])
Texel - llrrststT-Sn-rxrx (Silkie with a ringlet coat, a cobby body and a broad face) [NOT a long-haired teddy, different gene responsible]
American satin - L-rrststT-snsnRx- (American plus the satin gene)
Abyssinian satin - L-R-ststT-snsnRx- (Abyssinian plus the satin gene)
Teddy satin - L-rrststttsnsnRx- (Teddy plus the satin gene)
Silkie satin - llrrststT-snsnRx- (Silkie plus the satin gene)
Peruvian satin - llR-ststT-snsnRx- (Peruvian plus the satin gene)
Swiss was approved a COD (certificate of development) by ACBA in 2023 (first presentation will be 2025, 2-3 successful presentations at the annual convention are required for acceptance as a show breed). --rrststT-Sn-Rx-swsw The Swiss breed are semilonghair (about 3 inch hair length) - it remains unclear whether this is genetically a longhaired breed (ll = indeterminate growth means the hair will keep growing) prone to breakage at a certain length, a shorthaired breed (L- means the hair reaches a predetermined length and stops growing) with modifiers that increase hair length, a direct result of sw modifying hair length, a novel gene at the L/l locus, or a completely separate gene which causes a periodic molt. Purebred Swiss breed true (all semilonghair), so this is not the result of a heterozygous (e.g., Ll) genotype even though often the hair on the rear is longer than on the front (considered a fault). Unlike texel or lunkarya which drape under the weight of longer hair, the swiss fur stands erect giving a 'puffball' appearance.
Lunkarya - llrrststT-Sn-Rx- +Cu- a new gene discovered in Sweden (Cu) is the basis of the lunkarya, which looks like a texel with a looser curl. This is a separate gene from Rex or teddy or Swiss, though with a similar 'rexoid' look. Lunkarya was approved a COD by ACBA in 2024.
English crested -- unlike our White-crested, English crested are not required to have the modifier which turns the crest white. So the crest appears the same color as the body. Crested were approved a COD by ACBA in 2024.
Other genetic combinations exist, but are not accepted by ACBA. Some are accepted elsewhere in the world. A few of the more common ones...
Rex - L-rrststT-Sn-rxrx (similar to a teddy, but slightly rougher texture)
Merino - llrrSt-T-Sn-rxrx (a coronet with ringlets - or a texel with a crest)
Alpaca - llR-ststT-Sn-rxrx (a curly Peruvian - or a texel with rosettes)
Somali - L-R-ststT-Sn-rxrx (a rex with rosettes)
Crested satins - L-rrSt-T-snsnRx-
Coronet satin - llrrSt-T-snsnRx-
Texel satin - llrrsrstT-snsnrxrx
Sheba Mini-Yak - llR-ststT-Sn-Rx- (a variation on Peruvian retaining more rosettes due to a recessive modifier resulting in a more 'tousled' appearance) crosses between abyssinians and longhaired cavies often result in an appearance closer to the sheba than to the Peruvian.
Ridgeback - L-R-ststT-Sn-Rx- (a variation on Abyssinian in which modifier genes restrict the rosettes to produce a single ridge along the spine)
Skinny - a separate recessive gene which causes cavies to be born (and remain) hairless. Skinny pigs often grow some sparse hair on the nose and feet. This gene originated in teddies, so many skinnies are hiding teddy genotypes.
Baldwin - a separate recessive gene which causes cavies to lose their hair (usually at a few weeks old). Baldwins originated in white-crested cavies and often hide white-crested genotypes. Skinny and Baldwin are separate genes -- crossing skinnies and baldwins results in cavies that have hair (but are carriers for both types of hairlessness).
Lakeland - a guinea pig which is born with teddy fur, loses it's hair at ~3 weeks old, and then regrows its hair. This is a carrier for the skinny gene. Not all skinny carriers are Lakelands, but all Lakelands are skinny carriers.
Werewolf - a guinea pig which is partially hairless - typically with more hair than a skinny. This is a genetic skinny pig, but has modifiers that allow some hair to remain or regrow. Typically born with more hair than usual for a skinny pig but often lose this extra hair in the first 3-4 weeks, then often re-grow it into adulthood. Hair may be affected hormonally - some skinnies grow hair only during pregnancy, some werewolves lose their hair following pregnancy.
Why don't we have rexes, merinos, alpacas, coronet satins or white crested satins?
ARBA/ACBA decided that a single gene difference (e.g., Rx and Sn) which are easily bred to the base type (as in breeding an American to an American satin) should not be sufficient to constitute a separate breed. Those breeds which had been accepted prior to this ruling (e.g., the accepted satins) were grandfathered in - but no new satin or rex breeds will be accepted unless the rule changes.
Cavy Color and Pattern Genetics
Way more genes, alleles and co-dominant traits, and gene interactions than with rabbits...hang on.
Base Pattern genes (A and E)
For cavies, like rabbits and most mammals, the basic coat patterns are determined by the interaction of two gene pairs - A and E. These two genes work together to determine where the animal has the eumelanin pigment (aka base color - black, chocolate, blue, slate, lilac and beige) and where it has phaeomelanin pigment (aka marking color - red, orange, gold, cream and white). The base color and marking color are determined by the color genes (descibed below after A and E series genes and interactions). For now, we are going to discuss just A and E while holding the base color to black and marking color to red (B-C-P-D) which are the dominant colors in cavies.
Pattern Gene (A series)
Similar to the pattern series in rabbits, but we add an extra allele and change the rules just a bit.
A is the most dominant gene and results in an agouti animal -- black- or chocolate-based main color with red-series tips and a solid 'belly band' with just the red-series color. [A note for those coming from rabbits - agouti cavies are similar but not quite the same as an agouti rabbit. Hairs are a dark-series color plus red-series tip, more similar to the steel coat in lacking the 'rings' of an agouti rabbit - but they do have the belly band like agouti rabbits.]
Ar is recessive to A but dominant over the following alleles. ArAr cavies (called solids) look a lot like agoutis - until you flip them over. The ring pattern in these animals extends through the belly region, so the hair on the entire body looks the same. [A note for those coming from rabbits, the term 'solid' is used differently in the two species! In rabbits solid is used as the opposite of broken (no white patches), in cavies a solid is a ticked pattern over the entire body with no markings - think steel rabbits!]
at is the tan pattern allele. It gives you an animal that looks a LOT like a tan pattern rabbit - solid colored back (e.g., black or chocolate), tan belly, eyes circles and tan spots by the ears. Tan is dominant over self (the last allele in the series - below) but CO-dominant with A and Ar. Thus an animal with genotype Aat looks like an agouti except that you still get the tan eye circles and spots by the ears (a fault). Arat also looks like an agouti except you get the eye circles and pea spots (a fault). atat and ata both give the tan pattern.
a is the final allele in the series. Just like in rabbits, it is the self gene, resulting in a solid colored cavy.
So far:
AA and AAr and Aa = agouti
ArAr and Ara = solids
Aat and Arat = unaccepted mismarked agouti and 'false agouti'
atat and ata = tan pattern
aa = self (aka eumelanin self)
Prior to the addition of tan, the three A-alleles in cavies were treated as a simple dominance series. The A-series is actually entirely co-dominant. If the two alleles of a heterozygous pair (two different alleles in the same animal) give different instructions -- one to produce eumelanin (base color) and the other to produce phaeomelanin (marking color) - phaeomelanin always wins. The 'recessive' a allele codes only for eumelanin and will be overwritten by any other allele that calls for phaeomelanin. Since the solid allele (Ar) has phaeomelanin in fewer locations than agouti (A) and no phaeomelanin in any locations that A has eumelanin, the Ar allele acts as though it were recessive to A. But in the case of the tan allele (at), the tan pattern has phaeomelanin in places where the A and Ar have eumelanin (most notably the peaspots) as well as eumelanin in places where A and Ar have phaeomelanin (most of the coat except tipping).
CAUTION - with the rise of popularity in tan pattern cavies, breeders of agoutis and especially solids should be on the lookout for mismarked animals with peaspots. This is especially true for breeders of agoutis -- it is now increasingly possible to have a cavy sold as an agouti that is a genetic solid carrying tan -- Arat cavies appear agouti (except that it has peaspots which may be small enough to be easily overlooked) even though they do NOT have any agouti genes!
A is the most dominant gene and results in an agouti animal -- black- or chocolate-based main color with red-series tips and a solid 'belly band' with just the red-series color. [A note for those coming from rabbits - agouti cavies are similar but not quite the same as an agouti rabbit. Hairs are a dark-series color plus red-series tip, more similar to the steel coat in lacking the 'rings' of an agouti rabbit - but they do have the belly band like agouti rabbits.]
Ar is recessive to A but dominant over the following alleles. ArAr cavies (called solids) look a lot like agoutis - until you flip them over. The ring pattern in these animals extends through the belly region, so the hair on the entire body looks the same. [A note for those coming from rabbits, the term 'solid' is used differently in the two species! In rabbits solid is used as the opposite of broken (no white patches), in cavies a solid is a ticked pattern over the entire body with no markings - think steel rabbits!]
at is the tan pattern allele. It gives you an animal that looks a LOT like a tan pattern rabbit - solid colored back (e.g., black or chocolate), tan belly, eyes circles and tan spots by the ears. Tan is dominant over self (the last allele in the series - below) but CO-dominant with A and Ar. Thus an animal with genotype Aat looks like an agouti except that you still get the tan eye circles and spots by the ears (a fault). Arat also looks like an agouti except you get the eye circles and pea spots (a fault). atat and ata both give the tan pattern.
a is the final allele in the series. Just like in rabbits, it is the self gene, resulting in a solid colored cavy.
So far:
AA and AAr and Aa = agouti
ArAr and Ara = solids
Aat and Arat = unaccepted mismarked agouti and 'false agouti'
atat and ata = tan pattern
aa = self (aka eumelanin self)
Prior to the addition of tan, the three A-alleles in cavies were treated as a simple dominance series. The A-series is actually entirely co-dominant. If the two alleles of a heterozygous pair (two different alleles in the same animal) give different instructions -- one to produce eumelanin (base color) and the other to produce phaeomelanin (marking color) - phaeomelanin always wins. The 'recessive' a allele codes only for eumelanin and will be overwritten by any other allele that calls for phaeomelanin. Since the solid allele (Ar) has phaeomelanin in fewer locations than agouti (A) and no phaeomelanin in any locations that A has eumelanin, the Ar allele acts as though it were recessive to A. But in the case of the tan allele (at), the tan pattern has phaeomelanin in places where the A and Ar have eumelanin (most notably the peaspots) as well as eumelanin in places where A and Ar have phaeomelanin (most of the coat except tipping).
CAUTION - with the rise of popularity in tan pattern cavies, breeders of agoutis and especially solids should be on the lookout for mismarked animals with peaspots. This is especially true for breeders of agoutis -- it is now increasingly possible to have a cavy sold as an agouti that is a genetic solid carrying tan -- Arat cavies appear agouti (except that it has peaspots which may be small enough to be easily overlooked) even though they do NOT have any agouti genes!
E series (E/ep/e)
Similar to rabbits in that this is how to get red color, but works a bit differently!
E is the dominant allele - EE results in the normal patterns above determined by the A-series genes.
ee, called non-extension, is the recessive genotype. As with rabbits, it extends the middle band and removes the base (black/chocolate) color, and does not remove dark eye color. Unlike rabbits, it does not lighten the belly color or show any other markings (eye circles, light inner ears, light belly, light underside to the tail are common in most red/orange/fawn/cream rabbits). A non-extension cavies looks like a self, but in the marking color, not the base color.
In cavies, unlike rabbits, ee is epistatic to the A-series -- regardless of A-, Ar-, at- or aa an ee genotype has only one color. As in rabbits, A-ee gives red. So does Ar-ee. Unlike rabbits, so does at-ee (no fox, just red). Also unlike rabbits, so does aaee (no tort, just red).
In cavies, aaee is the preferred genotype for red-based colors (but don't be shocked if a red proves to be hiding agouti, many do!).
Under the ACBA standard, the non-extension 'reds' are broken into subgroups based on the 'dilution' (combination of B, C and P genes): red, red-eyed orange, gold, cream and white (see below).
We've also got an intermediate allele in play - ep or partial extension.
If familiar with harlequin (ej) in rabbits, ep works somewhat similar, but NOT identical!
aaepep (with B-C- and P) gives a color that is called tortoiseshell in cavies (but is what we would call harlequin in rabbits) in which the animal has patches of black and red (requires some additional modifiers to make the patches look right) OR (depending on modifiers) can give brindle (interspersed black and red hairs). UNLIKE with harlequin rabbits, the A-series genes DOES show, so A-epep is has patches of agouti and patches of red (and Ar-epep is solid/red). Adding epep to tan (at-) results in extra tan marks. With colors and patterns other than black/red, epep is called broken (broken in cavies can be any two or more colors, not just a color and white).
Note that so far, I've just given the 'pure' E series genotypes - EE, epep and ee. That's because the dominance in this series isn't so simple.
Eep animals often (but not always) have stray red marks (like Vienna carriers and Vienna marks in rabbits). Some breeders of brindles report the Eep brindles can often not be distinguished from good brindles other than a tendency to throw a significant number solid black babies (even when there is no other possible source for an E-gene, such as brindle x brindle).
Ee can also (less commonly and smaller when present) also result in stray red marks.
epe pretty much looks like epep -- since the ep already causes red patches, its hard to tell whether or not the e is adding a few extra - but sources argue that an epe cavy will be 'more red' than the epep.
Recap - Like rabbits, the 'e' series gene is responsible for red color. But it works much more like the rabbit Vienna (BEW) gene - completely covering other colors and patterns and, when 'carried,' occasionally showing though as stray marks.
--ee = phaeomelanin selfs (red, orange, gold, cream, white as determined by the color genes below)
aaEE = eumelanin selfs (black, blue, slate, lilac, chocolate and beige as determined by color genes below)
aaep- = patches of 2 self colors, one eumelanin and 1 phaeomelanin.
atatEE and ataEE = tan pattern
atatep- and ataep- = broken tan pattern (tan with extra markings - base and marking colors determined by color genes below)
ArArEE and AraEE = solid
ArArep- and Araep- = broken solid (patches of solid and patches of pheomelanin)
A-EE = agouti
A-ep- = broken agouti (patches of agouti and patches of pheomelanin)
aaEep and aaEe - eumelanin self, often mismarked with stray phaeomelanin
at-Eep - tan pattern, often mismarked
at-Ee - tan pattern, possibly mismarked, but since red toes are allowed, this is typically a minor fault
Ar-Eep and Ar-Ee - solid, often mismarked with stray areas where ticking is missing
A-Eep - agouti, often mismarked with stray areas lacking ticking
A-Ee - agouti, possibly mismarked
AratEE - false agouti
AatEE - agouti, possible pea spots lacking ticking
For best show markings:
Tan pattern can usually be bred to a corresponding eumelanin self color but should not be bred to agoutis or solids.
E is the dominant allele - EE results in the normal patterns above determined by the A-series genes.
ee, called non-extension, is the recessive genotype. As with rabbits, it extends the middle band and removes the base (black/chocolate) color, and does not remove dark eye color. Unlike rabbits, it does not lighten the belly color or show any other markings (eye circles, light inner ears, light belly, light underside to the tail are common in most red/orange/fawn/cream rabbits). A non-extension cavies looks like a self, but in the marking color, not the base color.
In cavies, unlike rabbits, ee is epistatic to the A-series -- regardless of A-, Ar-, at- or aa an ee genotype has only one color. As in rabbits, A-ee gives red. So does Ar-ee. Unlike rabbits, so does at-ee (no fox, just red). Also unlike rabbits, so does aaee (no tort, just red).
In cavies, aaee is the preferred genotype for red-based colors (but don't be shocked if a red proves to be hiding agouti, many do!).
Under the ACBA standard, the non-extension 'reds' are broken into subgroups based on the 'dilution' (combination of B, C and P genes): red, red-eyed orange, gold, cream and white (see below).
We've also got an intermediate allele in play - ep or partial extension.
If familiar with harlequin (ej) in rabbits, ep works somewhat similar, but NOT identical!
aaepep (with B-C- and P) gives a color that is called tortoiseshell in cavies (but is what we would call harlequin in rabbits) in which the animal has patches of black and red (requires some additional modifiers to make the patches look right) OR (depending on modifiers) can give brindle (interspersed black and red hairs). UNLIKE with harlequin rabbits, the A-series genes DOES show, so A-epep is has patches of agouti and patches of red (and Ar-epep is solid/red). Adding epep to tan (at-) results in extra tan marks. With colors and patterns other than black/red, epep is called broken (broken in cavies can be any two or more colors, not just a color and white).
Note that so far, I've just given the 'pure' E series genotypes - EE, epep and ee. That's because the dominance in this series isn't so simple.
Eep animals often (but not always) have stray red marks (like Vienna carriers and Vienna marks in rabbits). Some breeders of brindles report the Eep brindles can often not be distinguished from good brindles other than a tendency to throw a significant number solid black babies (even when there is no other possible source for an E-gene, such as brindle x brindle).
Ee can also (less commonly and smaller when present) also result in stray red marks.
epe pretty much looks like epep -- since the ep already causes red patches, its hard to tell whether or not the e is adding a few extra - but sources argue that an epe cavy will be 'more red' than the epep.
Recap - Like rabbits, the 'e' series gene is responsible for red color. But it works much more like the rabbit Vienna (BEW) gene - completely covering other colors and patterns and, when 'carried,' occasionally showing though as stray marks.
--ee = phaeomelanin selfs (red, orange, gold, cream, white as determined by the color genes below)
aaEE = eumelanin selfs (black, blue, slate, lilac, chocolate and beige as determined by color genes below)
aaep- = patches of 2 self colors, one eumelanin and 1 phaeomelanin.
atatEE and ataEE = tan pattern
atatep- and ataep- = broken tan pattern (tan with extra markings - base and marking colors determined by color genes below)
ArArEE and AraEE = solid
ArArep- and Araep- = broken solid (patches of solid and patches of pheomelanin)
A-EE = agouti
A-ep- = broken agouti (patches of agouti and patches of pheomelanin)
aaEep and aaEe - eumelanin self, often mismarked with stray phaeomelanin
at-Eep - tan pattern, often mismarked
at-Ee - tan pattern, possibly mismarked, but since red toes are allowed, this is typically a minor fault
Ar-Eep and Ar-Ee - solid, often mismarked with stray areas where ticking is missing
A-Eep - agouti, often mismarked with stray areas lacking ticking
A-Ee - agouti, possibly mismarked
AratEE - false agouti
AatEE - agouti, possible pea spots lacking ticking
For best show markings:
Tan pattern can usually be bred to a corresponding eumelanin self color but should not be bred to agoutis or solids.
Genes affecting base color (Eumelanin)
The following discussion assumes aaEE (eumelanin self). But the same rules and gene combinations affect the base color of agouti, solid and tan as well.
Black/Chocolate (B/b)
Simplest first. For those used to rabbit color genetics, let's do the B gene first. It comes in two forms (alleles). B for black and b for chocolate. Cavies that are BB or Bb are black, bb are chocolate (chocolate also adds a ruby glow to the eyes). Just like with rabbits, we can do lots of things with other genes to modify these two base colors.
Pink-eyed Dilute (P/pg/p)
Unlike with rabbits (now with an exception for lutino), pink eyes aren't restricted to white animals. The recessive p gene lightens the black portions of the coat color (but not all the way to white) and causes pink eyes. It doesn't lighten red portions of the coat.
[For those familiar with the rare rabbit colors, 'p' is the equivalent of the lutino gene in rabbits -- so a lilac cavy is the equivalent of a dove lutino rabbit, not a lilac rabbit!]
So...
Black = B-P-
Chocolate = bbP-
Lilac = B-pp
beige = bbpp
Please note - In cavies the eye color caused by the pink-eyed dilute gene (pp) or the himalayan gene (below ch) is referred to as PINK-eyed - even though it looks pretty much identical to what we would call 'RED-eyed white' in rabbits. This is most likely because in cavies the cr gene causes RED eyes of a deep red shade (closer to what we call 'ruby cast' in rabbits). In rabbits, red eyes are found only in whites and himalayans (except for lutino rabbits) and are due to the action of either the himalayan (ch) or albino (c) gene -- both on the C-series. In cavies, pink-eyes are due to EITHER the p gene (described here) or the himalayan gene (ch - described below) - the true albino gene c does not exist in cavies.
The slate color in American cavies is attributed to a genotype pgpg - which is an intermediate allele in the P series.
P>pg>=p
Note that pg is NOT completely dominant to p. pgp often look like true slates, but may be somewhat lighter in tone than desired and often have a paler eye color (intermediate between the desired dark ruby cast and the pink-eye of lilac) -- this effect appears to be more pronounced when mixed with other 'diluting' genes (we've found it difficult to get dark enough color on the slate martens).
The pg allele lightens black to a slate-blue color intermediate between black and lilac. The pg allele lightens IRIS color to a slate-grey and pupil color to deep ruby (NOT blue). In the US, ACBA originally accepted the pgpg genotype ONLY in slate tan; martens and otters were added later -- as of 2024, slate will also be accepted in self, agoutis, solids, broken, Dutch, roan, dalmatian, and californian (basically accepted as a base color for all patterns, just as black, chocolate, lilac and beige).
When slate is crossed with chocolate, the result in the first generation defaults to black (BbPpg) but later generations can recombine to
pgpgbb - pg lightens chocolate to a caramel color intermediate between chocolate and beige (typically called caramel, though carob, taupe and coffee have also been used as names for this color in various places). NO caramels are accepted by ACBA. For this reason, slates should never be crossbred with chocolate or beige varieties in any breed or pattern.
The US was the only place in the cavy world to refer to the slate color as blue (2010-2020). As of 2021, the ARBA/ACBA changed the standard to call pgpg genotypes slate, to match the rest of the world. Expect it may take several years for pedigrees to correct. The rest of the cavy world reserved the term 'blue' in the hopes that someday a D-mutation would arise. Their patience has paid off as a new mutation found in tortoiseshells in Denmark appears to be true blue (dd). Self blues are a COD (certificate of development - can be shown exhibition, but not yet fully accepted) variety in the ACBA - their first successful presentation was in October 2023.
[For those familiar with the rare rabbit colors, 'p' is the equivalent of the lutino gene in rabbits -- so a lilac cavy is the equivalent of a dove lutino rabbit, not a lilac rabbit!]
So...
Black = B-P-
Chocolate = bbP-
Lilac = B-pp
beige = bbpp
Please note - In cavies the eye color caused by the pink-eyed dilute gene (pp) or the himalayan gene (below ch) is referred to as PINK-eyed - even though it looks pretty much identical to what we would call 'RED-eyed white' in rabbits. This is most likely because in cavies the cr gene causes RED eyes of a deep red shade (closer to what we call 'ruby cast' in rabbits). In rabbits, red eyes are found only in whites and himalayans (except for lutino rabbits) and are due to the action of either the himalayan (ch) or albino (c) gene -- both on the C-series. In cavies, pink-eyes are due to EITHER the p gene (described here) or the himalayan gene (ch - described below) - the true albino gene c does not exist in cavies.
The slate color in American cavies is attributed to a genotype pgpg - which is an intermediate allele in the P series.
P>pg>=p
Note that pg is NOT completely dominant to p. pgp often look like true slates, but may be somewhat lighter in tone than desired and often have a paler eye color (intermediate between the desired dark ruby cast and the pink-eye of lilac) -- this effect appears to be more pronounced when mixed with other 'diluting' genes (we've found it difficult to get dark enough color on the slate martens).
The pg allele lightens black to a slate-blue color intermediate between black and lilac. The pg allele lightens IRIS color to a slate-grey and pupil color to deep ruby (NOT blue). In the US, ACBA originally accepted the pgpg genotype ONLY in slate tan; martens and otters were added later -- as of 2024, slate will also be accepted in self, agoutis, solids, broken, Dutch, roan, dalmatian, and californian (basically accepted as a base color for all patterns, just as black, chocolate, lilac and beige).
When slate is crossed with chocolate, the result in the first generation defaults to black (BbPpg) but later generations can recombine to
pgpgbb - pg lightens chocolate to a caramel color intermediate between chocolate and beige (typically called caramel, though carob, taupe and coffee have also been used as names for this color in various places). NO caramels are accepted by ACBA. For this reason, slates should never be crossbred with chocolate or beige varieties in any breed or pattern.
The US was the only place in the cavy world to refer to the slate color as blue (2010-2020). As of 2021, the ARBA/ACBA changed the standard to call pgpg genotypes slate, to match the rest of the world. Expect it may take several years for pedigrees to correct. The rest of the cavy world reserved the term 'blue' in the hopes that someday a D-mutation would arise. Their patience has paid off as a new mutation found in tortoiseshells in Denmark appears to be true blue (dd). Self blues are a COD (certificate of development - can be shown exhibition, but not yet fully accepted) variety in the ACBA - their first successful presentation was in October 2023.
Blue-Dilution (D/d)
Blue cavies are a very dark shade of blue-grey -- nearly navy. This is a MUCH darker tone than can be achieved with pgpg. Unlike their blue rabbit counterparts, the eyes are not faded to blue-grey, but remain fully dark.
I have found no evidence that blue has been biochemically linked to the equivalent D/d locus in rabbits and no scientific publications are yet available for this mutation; however most breeders are using D/d as the symbol.
Currently only the black-based blue self has a COD moving toward inclusion in the ACBA standard (as of 2023) -- aaB-C-ddP-E-.
In Europe, blues have been crossed to many other base colors resulting in
B-P-dd = blue
B-pgpgdd = lavender
B-ppdd = silverblue
bbP-dd = Isabel (aka violet)
bbpgpgdd = mink
bbppdd = mink?
With blues currently accepted (COD) only on the black-base (BBPP) self (aa) in the US, blues should not be crossed to other patterns and base-colors except for self-black if one doesn't want to produce unshowable colors.
Unlike chocolate (bb), lilac (pp), slate (pgpg) and beige (bbpp), blue (dd) has a strong affect on red-series colors as well. This will be noted below.
I have found no evidence that blue has been biochemically linked to the equivalent D/d locus in rabbits and no scientific publications are yet available for this mutation; however most breeders are using D/d as the symbol.
Currently only the black-based blue self has a COD moving toward inclusion in the ACBA standard (as of 2023) -- aaB-C-ddP-E-.
In Europe, blues have been crossed to many other base colors resulting in
B-P-dd = blue
B-pgpgdd = lavender
B-ppdd = silverblue
bbP-dd = Isabel (aka violet)
bbpgpgdd = mink
bbppdd = mink?
With blues currently accepted (COD) only on the black-base (BBPP) self (aa) in the US, blues should not be crossed to other patterns and base-colors except for self-black if one doesn't want to produce unshowable colors.
Unlike chocolate (bb), lilac (pp), slate (pgpg) and beige (bbpp), blue (dd) has a strong affect on red-series colors as well. This will be noted below.
The Phaeomelanin-Dilution Gene - C series
The C-series gene in cavies seems to have been widely called the 'dilution gene' before the discovery of the d mutation in cavies - and both pg and pp are also sometimes called 'dilutes' and in some cases bb is called dilute too -- which does create some potential confusion. In other mammals, the C-locus is often called the albino locus, but the actual albino allele (c) doesn't exist in cavies. For now, we call the C-series in cavies 'phaeomelanin-dilution' or 'C-dilutions' because they MOSTLY affect the red pigments (phaeomelanin).
Although biochemically similar to the C-series of rabbits and the 'wild-type' dominant C is used in both, cavies have novel mutations (ck, cd) that aren't seen in rabbits, are missing alleles common in rabbits (cchl and c), and even the ones that are present have different names cchd~=cr).
Point #1 - the C series alleles all have a similar effect - lightening pigment color. They can operate on the fur color, the eye color or both.
Point #2 - C, the 'normal color' allele is dominant and can hide any of the others.
Point #3 - the rest of the whole series is co-dominant - mixing alleles gives you intermediate degrees of dilution.
The alleles:
C is the normal color (as dictated by ABE and P genes)
ck is dark dilute. It lightens the coat a bit, but does not change eyes.
cd is the light dilute (aka buff dilute). It lightens the coat significantly more but does not change eyes
cr is the ruby eyed dilute (aka dark-eyed white dilute). It lightens the coat to white or near white and shifts the eyes to a ruby red (dark eyes with a ruby cast, not pink). [cr is a near-equivalent of cchd in rabbits!]
ch is the himi gene, responsible for both himalayans and pink-eyed whites.
[For rabbit folks - there is no cavy gene equivalent to cchl or c, but similar end results - sable and pink-eyed white cavies - can be achieved through gene combinations]
A quick note on albino - The true albino gene (a recessive usually symboled c) which all by itself (without the assistance of any other gene) completely shuts down the production of pigments (both eumelanin and phaeomelanin) is unknown in cavies. Although the red-eyed white of rabbits LOOKS identical to the pink-eyed white of cavies, REW rabbits are true genetic albinos, while PEW cavies are not because they require at least the interaction of two gene pairs chch + ee to get rid of all the pigments.
I'm going to start with the most recessive first - himalayan (chch): The himalayan genotype (chch) has 3 distinct effects on color (1) it removes all phaeomelanin (red/yellow pigments) (2) it removes all eumelanin from the eyes - himalayans always have pink eyes (3) it restricts eumelanin to the points (only ears, nose and feet have color).
Show quality himalayan (variety) is always accompanied by aa (discussed below) and EE (above) for proper show-types (aka maximum point color). epep, epe, Eep typically cause mismarkings such as a white foot or white ear. Ee may also have white toes.
Black + chch = aaB-P-E-chch = himalayan - as with the rabbit of that name, the result is a white cavy with black points (nose, ears, feet) and pink eyes.
Chocolate + chch = aabbP-E-chch = chocolate himalayan (not showable in ACBA standard, but is in several other countries)
Blue + chch = aaB-P-E-chch = blue himalayan (not currently approved for show in ACBA standard - likely to follow acceptance of blue self)
slate +chch = aa--pgpgE-chch = also not currently accepted for show in the ACBA standard
lilac/beige + chch = aa--ppE-chch = not approved for show in ACBA standard due to point color fading
Note - theoretically, himalayans can exist in any of the 12 base colors above, but it is unlikely that any of the lighter shades will ever be accepted in ACBA because they are prone to faded points (additive effect of dilutions) and become difficult to distinguish.
Next I'm going to discuss how the above appear with --ee. If you recall from above, all of the ee genotypes show only the marking color as a 'phaeomelanin self'. Without the 'distraction' of the eumelanin, it is easiest to see the true effect of the C-series genes which operates mainly on eumelanin. For the eumelanin selfs (aaEE) the effect of the C-series genes is invisible. For the other base patterns (agouti, solid, tan, brokens) C-series is expressed primarily in the marking color, following the same patterns seen in these phaeomelanin self types.
ee + chch = pink-eyed white (the chch removes all the red color and turns the eyes pink, the ee removes the point color).
Note- all chchee are pink-eyed white, but not all pink-eyed white are chchee (other gene combinations can also give pink-eyed white - see below)
Next the ruby-eyed gene (crcr): crcr basically turns all red (phaeomelanin) pigments to white while leaving most of the eumelanin pigments.
This gene may cause slight fading of eumelanin self colors (a fault, not a disqualification).
crch genotypes result in a slight lightening of the coat except over the points and a ruby cast to the eyes. This effect is invisible on the phaeomelanin selfs but can be pronounced on the E- and ep- genotypes. This shading is referred to as sable. Sables are not accepted in the ACBA (here they are just considered to be 'uneven colored selfs' and often disqualified for the ruby cast eyes) - but are accepted elsewhere in the world. Sables often take time for the point color to develop and young black-sables can be mistaken for slate.
The ck and cd alleles produce color dilutions that don't affect eye color and are definitely co-dominant (interacting with one another). Searle (1964) found that cdcd caused substantial fading of black pigments while ckck caused only slight fading of black pigments. Separating the two can be difficult, however given other modifiers (rufus and umbrous) can easily cause their effects to overlap. I do not discuss ck separately here - cd can throughout be read as referring to either cd or ck. Theoretically, cd would be preferred for the non-extension selfs (gold, cream) where pigment on the ears is a potential disqualification but ck preferred on otters where fading of the top color is a fault.
cdcd (or ckck) lightens red to gold. [note https://www.no-strings.org/pigs/genetics_web.htm states cdcd gives the 'correct gold shading'. Note that gold (UK = buff/saffron) is NOT included in the color chart for dilute agouti/solids and is not listed as a marking color for tan pattern, however, most judges would only fault, not disqualify for the in-between shade.
cdcr further lightens gold to cream. Because this is a heterozygous genotype, creams will not breed true -- cream x cream will always give some white (crcr) and some gold (cdcd).
cdch gives nearly the same shade of cream as cdcr. However, it markedly fades the black pigments on the body (darker points) in a pattern called sepia.
Although biochemically similar to the C-series of rabbits and the 'wild-type' dominant C is used in both, cavies have novel mutations (ck, cd) that aren't seen in rabbits, are missing alleles common in rabbits (cchl and c), and even the ones that are present have different names cchd~=cr).
Point #1 - the C series alleles all have a similar effect - lightening pigment color. They can operate on the fur color, the eye color or both.
Point #2 - C, the 'normal color' allele is dominant and can hide any of the others.
Point #3 - the rest of the whole series is co-dominant - mixing alleles gives you intermediate degrees of dilution.
The alleles:
C is the normal color (as dictated by ABE and P genes)
ck is dark dilute. It lightens the coat a bit, but does not change eyes.
cd is the light dilute (aka buff dilute). It lightens the coat significantly more but does not change eyes
cr is the ruby eyed dilute (aka dark-eyed white dilute). It lightens the coat to white or near white and shifts the eyes to a ruby red (dark eyes with a ruby cast, not pink). [cr is a near-equivalent of cchd in rabbits!]
ch is the himi gene, responsible for both himalayans and pink-eyed whites.
[For rabbit folks - there is no cavy gene equivalent to cchl or c, but similar end results - sable and pink-eyed white cavies - can be achieved through gene combinations]
A quick note on albino - The true albino gene (a recessive usually symboled c) which all by itself (without the assistance of any other gene) completely shuts down the production of pigments (both eumelanin and phaeomelanin) is unknown in cavies. Although the red-eyed white of rabbits LOOKS identical to the pink-eyed white of cavies, REW rabbits are true genetic albinos, while PEW cavies are not because they require at least the interaction of two gene pairs chch + ee to get rid of all the pigments.
I'm going to start with the most recessive first - himalayan (chch): The himalayan genotype (chch) has 3 distinct effects on color (1) it removes all phaeomelanin (red/yellow pigments) (2) it removes all eumelanin from the eyes - himalayans always have pink eyes (3) it restricts eumelanin to the points (only ears, nose and feet have color).
Show quality himalayan (variety) is always accompanied by aa (discussed below) and EE (above) for proper show-types (aka maximum point color). epep, epe, Eep typically cause mismarkings such as a white foot or white ear. Ee may also have white toes.
Black + chch = aaB-P-E-chch = himalayan - as with the rabbit of that name, the result is a white cavy with black points (nose, ears, feet) and pink eyes.
Chocolate + chch = aabbP-E-chch = chocolate himalayan (not showable in ACBA standard, but is in several other countries)
Blue + chch = aaB-P-E-chch = blue himalayan (not currently approved for show in ACBA standard - likely to follow acceptance of blue self)
slate +chch = aa--pgpgE-chch = also not currently accepted for show in the ACBA standard
lilac/beige + chch = aa--ppE-chch = not approved for show in ACBA standard due to point color fading
Note - theoretically, himalayans can exist in any of the 12 base colors above, but it is unlikely that any of the lighter shades will ever be accepted in ACBA because they are prone to faded points (additive effect of dilutions) and become difficult to distinguish.
Next I'm going to discuss how the above appear with --ee. If you recall from above, all of the ee genotypes show only the marking color as a 'phaeomelanin self'. Without the 'distraction' of the eumelanin, it is easiest to see the true effect of the C-series genes which operates mainly on eumelanin. For the eumelanin selfs (aaEE) the effect of the C-series genes is invisible. For the other base patterns (agouti, solid, tan, brokens) C-series is expressed primarily in the marking color, following the same patterns seen in these phaeomelanin self types.
ee + chch = pink-eyed white (the chch removes all the red color and turns the eyes pink, the ee removes the point color).
Note- all chchee are pink-eyed white, but not all pink-eyed white are chchee (other gene combinations can also give pink-eyed white - see below)
Next the ruby-eyed gene (crcr): crcr basically turns all red (phaeomelanin) pigments to white while leaving most of the eumelanin pigments.
This gene may cause slight fading of eumelanin self colors (a fault, not a disqualification).
crch genotypes result in a slight lightening of the coat except over the points and a ruby cast to the eyes. This effect is invisible on the phaeomelanin selfs but can be pronounced on the E- and ep- genotypes. This shading is referred to as sable. Sables are not accepted in the ACBA (here they are just considered to be 'uneven colored selfs' and often disqualified for the ruby cast eyes) - but are accepted elsewhere in the world. Sables often take time for the point color to develop and young black-sables can be mistaken for slate.
The ck and cd alleles produce color dilutions that don't affect eye color and are definitely co-dominant (interacting with one another). Searle (1964) found that cdcd caused substantial fading of black pigments while ckck caused only slight fading of black pigments. Separating the two can be difficult, however given other modifiers (rufus and umbrous) can easily cause their effects to overlap. I do not discuss ck separately here - cd can throughout be read as referring to either cd or ck. Theoretically, cd would be preferred for the non-extension selfs (gold, cream) where pigment on the ears is a potential disqualification but ck preferred on otters where fading of the top color is a fault.
cdcd (or ckck) lightens red to gold. [note https://www.no-strings.org/pigs/genetics_web.htm states cdcd gives the 'correct gold shading'. Note that gold (UK = buff/saffron) is NOT included in the color chart for dilute agouti/solids and is not listed as a marking color for tan pattern, however, most judges would only fault, not disqualify for the in-between shade.
cdcr further lightens gold to cream. Because this is a heterozygous genotype, creams will not breed true -- cream x cream will always give some white (crcr) and some gold (cdcd).
cdch gives nearly the same shade of cream as cdcr. However, it markedly fades the black pigments on the body (darker points) in a pattern called sepia.
A note on D-series interactions. dd (blue) dilutes red-series pigments as well as the black. Some of the combinations of dd with C-loci genes have been given names in Europe. None are accepted by ACBA.
C- P- dd = amber
C- pp dd = apricot?
cdcd P- dd = mandarin
cdcr P- dd = champagne
C- P- dd = amber
C- pp dd = apricot?
cdcd P- dd = mandarin
cdcr P- dd = champagne
Base colors and Marking colors
Eumelanin, as controlled by the B/b, P/pg/p, and D/d gene combinations, defines the base colors. With the currently known genes, 12 base colors are possible, but under current ACBA standards only 5 (black, chocolate, slate, lilac and beige) are accepted for show with a 6th (blue) in the development (COD) process.
Phaeomelanin, as controlled by C/ck/cd/cr/ch and D/d gene combinations along with rufus factor (a multigenic modifier system that is not well defined) defines the marking colors. ACBA currently accepts 5 marking colors - red, orange, gold, cream and white.
Phaeomelanin, as controlled by C/ck/cd/cr/ch and D/d gene combinations along with rufus factor (a multigenic modifier system that is not well defined) defines the marking colors. ACBA currently accepts 5 marking colors - red, orange, gold, cream and white.
A note on the dilute agoutis and solids
ACBA currently accepts 13 color combinations in the category of dilute agouti (and dilute solid) these are achieved by combining the chocolate gene (b), pink-eyed dilute gene (p), the buff dilute gene (cd), and the ruby-eyed dilute gene (cr). All must be E- (ee turns completely red or white!).
Black series (BBP-)
with C- is not diluted at all - golden agouti = A-B-P-C-E- (shown as its own group)
lemon agouti (black with cream tips and dark eyes) - A-B-P-cdcrE- (shown as part of the dilute agouti group)
Note the cr dilution here is called silver agouti - A-B-P-cr-E- (shown as its own group rather than part of the dilutes)
Chocolate series (bbP-)
chocolate agouti (chocolate with red tips and dark eyes with a ruby cast) - A-bbP-C-
cream agouti (chocolate with cream tips and dark eyes with a ruby cast) - A-bbP-cd-
cinnamon agouti (chocolate with white tips and dark eyes with a ruby cast) - A-bbP-cr-
Lilac Series (B-pp)
gold/lilac argente (lilac with orange tips and pink eyes) - A-B-ppC-
lemon/lilac argente (lilac with cream tips and pink eyes) - A-B-ppcd-
white lilac argente (lilac with white tips and pink eyes) - A-B-ppcr-
Beige series (bbpp)
gold/beige argente (beige with orange tips and pink eyes) - A-bbppC-
lemon/beige argente (beige with cream tips and pink eyes) - A-bbppcd-
white/beige argente (beige with white tips and pink eyes) - A-bbppcr-
As of 2023, ACBA added slate to the list of accepted dilute agouti combinations
Slate series (B-pgpg)
gold/slate argente (slate with red tips and ruby/grey eyes) - A-B-pgpgC-
lemon/slate argente (slate with cream tips and ruby/grey eyes) - A-B-pgpgcd-
white/slate argente (slate with white tips and ruby/grey eyes) - A-B-pgpgcr-
For solids, replace the word agouti/argente with solid and the A- with Ar-. Keep in mind a dilute solid (Ar-) is NOT a dilute self (aa)! Solids have the same color hairs over their whole body, but each hair is made of two colors - base and tip.
Black series (BBP-)
with C- is not diluted at all - golden agouti = A-B-P-C-E- (shown as its own group)
lemon agouti (black with cream tips and dark eyes) - A-B-P-cdcrE- (shown as part of the dilute agouti group)
Note the cr dilution here is called silver agouti - A-B-P-cr-E- (shown as its own group rather than part of the dilutes)
Chocolate series (bbP-)
chocolate agouti (chocolate with red tips and dark eyes with a ruby cast) - A-bbP-C-
cream agouti (chocolate with cream tips and dark eyes with a ruby cast) - A-bbP-cd-
cinnamon agouti (chocolate with white tips and dark eyes with a ruby cast) - A-bbP-cr-
Lilac Series (B-pp)
gold/lilac argente (lilac with orange tips and pink eyes) - A-B-ppC-
lemon/lilac argente (lilac with cream tips and pink eyes) - A-B-ppcd-
white lilac argente (lilac with white tips and pink eyes) - A-B-ppcr-
Beige series (bbpp)
gold/beige argente (beige with orange tips and pink eyes) - A-bbppC-
lemon/beige argente (beige with cream tips and pink eyes) - A-bbppcd-
white/beige argente (beige with white tips and pink eyes) - A-bbppcr-
As of 2023, ACBA added slate to the list of accepted dilute agouti combinations
Slate series (B-pgpg)
gold/slate argente (slate with red tips and ruby/grey eyes) - A-B-pgpgC-
lemon/slate argente (slate with cream tips and ruby/grey eyes) - A-B-pgpgcd-
white/slate argente (slate with white tips and ruby/grey eyes) - A-B-pgpgcr-
For solids, replace the word agouti/argente with solid and the A- with Ar-. Keep in mind a dilute solid (Ar-) is NOT a dilute self (aa)! Solids have the same color hairs over their whole body, but each hair is made of two colors - base and tip.
White Spotted - S/s
The white spotted gene is a co-dominant gene used in the Dutch, broken and tortoiseshell & white varieties. Its a pretty straightforward co-dominant system...SS is the 'normal' genotype with no white spots. Ss produces an animal with less than 50% white -- anywhere from a small spot up to half white. ss produces an animal that is more than 50% white. Rarely, this may give an all white animal, but most often you get a white cavy with spots of color. Exactly how much white (within the ranges above) as well as the pattern of the white patches are determined by modifier genes.
Broken is the most basic color pattern to rely on the white-spotted gene (note for cavies, color combinations NOT including white - and so not using this gene - are also called and shown as broken). Showable broken cavies in white + color (and the color can be any self, red, agouti or solid - but not tan) must have a white patch at least as large as a 50 cent piece. The preferred (i.e., needed to win) patterns are those close to 50-50 (half white, half colored) with large patches. The truly ideal approaches the pattern we call harlequin in rabbits (only in this case colored and white). Winning broken cavies can thus be either Ss or ss but are unlikely to be produced at random (requires very careful selection from broken lines to get those ideal patches).
Tortoiseshell and white cavies (and other tri-colored cavies which are shown as brokens) also have the white-spotted gene in play along with the ep gene (harlequin - see above). As tri-colored cavies should ideally have just 1/3 of their color white, they should be all Ss. Again modifier genes are critical to get the preferred (winning) patterns.
Dutch marked cavies look a lot like Dutch rabbits. The Ss genotype gives the Dutch pattern, but again, modifiers are needed to get the marks in the right places, so you are unlikely to produce a Dutch-marked cavy out of brokens that aren't out of Dutch lines. Black Dutch are EE and red Dutch are ee.
Broken is the most basic color pattern to rely on the white-spotted gene (note for cavies, color combinations NOT including white - and so not using this gene - are also called and shown as broken). Showable broken cavies in white + color (and the color can be any self, red, agouti or solid - but not tan) must have a white patch at least as large as a 50 cent piece. The preferred (i.e., needed to win) patterns are those close to 50-50 (half white, half colored) with large patches. The truly ideal approaches the pattern we call harlequin in rabbits (only in this case colored and white). Winning broken cavies can thus be either Ss or ss but are unlikely to be produced at random (requires very careful selection from broken lines to get those ideal patches).
Tortoiseshell and white cavies (and other tri-colored cavies which are shown as brokens) also have the white-spotted gene in play along with the ep gene (harlequin - see above). As tri-colored cavies should ideally have just 1/3 of their color white, they should be all Ss. Again modifier genes are critical to get the preferred (winning) patterns.
Dutch marked cavies look a lot like Dutch rabbits. The Ss genotype gives the Dutch pattern, but again, modifiers are needed to get the marks in the right places, so you are unlikely to produce a Dutch-marked cavy out of brokens that aren't out of Dutch lines. Black Dutch are EE and red Dutch are ee.
Roan - Rn
Roan is a co-dominant gene. The 'normal' cavy colors all have the recessive genotype rnrn. Rnrn produces a roan kit in which the colored and white hairs are mixed together producing a speckled pattern. RnRn produces white pups with ruby-blue eyes, called 'lethal whites'. Unfortunately, RnRn kits earn the name 'lethal' -- often blind, with twisted teeth and other deformities. In most cases, these deformities are severe enough to limit quality of life and lethals should be put down. For this reason, roans should always be bred with a solid colored cavy (in the color you are trying to include in the roan) and never with another roan. This is the same type of breeding pattern we use in broken rabbits (breed broken to solid) when we try to avoid producing the unshowable charlies. But here it is much more serious as those deformed pups have to be put down.
Dalmatian is a variation on roan - in the US addition of some modifier genes cause the colored hairs to cluster into spots rather than mix evenly through the coat. There may be an alternative allele at the same locus that is more common in European dalmatians. Because the roan gene (or at least gene locus) is involved, you should never breed dalmatian to dalmatian or dalmatian to roan either.
Dalmatian is a variation on roan - in the US addition of some modifier genes cause the colored hairs to cluster into spots rather than mix evenly through the coat. There may be an alternative allele at the same locus that is more common in European dalmatians. Because the roan gene (or at least gene locus) is involved, you should never breed dalmatian to dalmatian or dalmatian to roan either.
Californian - K
Californian is a dominant gene that creates a mask of the eumelanin (black, chocolate, lilac, beige, slate, etc) pigment over all the points (nose, ears, feet). The gene has a degree of incomplete dominance (dose dependence) such that the markings are larger on the homozygous (KK) than on the heterozygous (Kk). Generally the smaller heterozygous markings are preferred! Babies are born without the mask markings, but they develop over the first two months. The Californian gene always creates a mask, but that mask can be hidden. (1) Ss and ss white spots remove mask pigment as well as the base color (mask can be hidden by white). (2) ep- the mask markings will develop where point color is red/orange/gold/cream, but on adults is easily mistaken for part of the base pattern. (3) Eumelanin-selfs (black, chocolate, lilac, beige), the mask being the same color as the base, makes it invisible (4) tan pattern californian (at-E- + K-) may be mistaken for poor markings as the mask only obscures the nostril and foot markings. (5) himalayan - black and chocolate based chch K- will still have the pink eyes and be considered himalayan, even though they are both genetically.
Under ACBA rules, only the 'phaeomelanin self' (ee) californians (red, orange, gold, cream and white body color with black, chocolate, slate, lilac and beige markings) are allowed for show.
Note that the eye color of californians must correspond to the point color. Black/white and chocolate/white californians must have dark eyes - this separates them from the accepted himalayan colors. Slate/white californians have dark ruby-grey eyes, lilac/white and beige/white californians have pink eyes.
Under ACBA rules, only the 'phaeomelanin self' (ee) californians (red, orange, gold, cream and white body color with black, chocolate, slate, lilac and beige markings) are allowed for show.
Note that the eye color of californians must correspond to the point color. Black/white and chocolate/white californians must have dark eyes - this separates them from the accepted himalayan colors. Slate/white californians have dark ruby-grey eyes, lilac/white and beige/white californians have pink eyes.
