Wrong color (dog breeding)

Boxer puppies: color according to the breed standard : yellow on the left , brindle on the right - according to the breed standard, no more than a third of the fur must be white.

Boxer puppy in white - neither eumelanin nor pheomelanin are stored in the fur . Usually the pigmentation of the eyelid rims is missing . White boxers are not allowed to breed; in exhibitions there are now extra classes for whites.

As off-color or color errors in pedigree dog breeding are coat colors of dogs which have in the respective FCI - breed standard are foreseen. For some dog breeds, the breed standard allows the full range of non-hazardous coat colors that occur in dogs for genetic reasons, for others several coat colors that are precisely defined in the standard are permitted, and for some breeds a specific coat color in narrowly defined variants is prescribed. The breed-typical eye colors as well as the desired coloring of the eyelid rims and the nose sponge can also be found in the respective breed standard.

Small areas of unwanted coloration are called color defects . Large areas or unwanted colorations affecting the whole body are called false colors . In the case of off-color puppies, both parents usually correspond to the FCI breed standard. According to the cynological definition, a dog with a wrong color is not a variety within pedigree dog breeding , because an additional permitted characteristic must be described in the breed standard. The term false color is not a veterinary term. There are both dogs with false colors who are healthy and those in which certain color genes lead to malformations or diseases due to polyphenia . A particular problem arises from the fact that one and the same phenotype in terms of coat color can arise from different genes or variants of an allele . The terms false color and color defects are also used in the breeding of other animal species, for example horses .

Genetic causes

Two inheritance schemes for the inheritance of a false color (in this example white ) with and without expression in the phenotype.
Left inheritance pattern: One parent is pure-bred, the other heterozygous . All offspring of such a mating carry the Nonstandard staining, with 50% again plant carriers ( conductors ). Right inheritance scheme: When two carriers are mated , an average of 25% of the puppies have the wrong color (split rule). Two out of three with the standard color are themselves carriers.

The crossing schemes are simplified in that the inheritance of coat colors as monogenic inheritance is represented, although this polygenic arise: Here, the recessive staining by a single homozygous vorliegendes allele are triggered, which prevents the formation of one or more pigments or alters their distribution.

Wrong colors can arise through spontaneous mutation . Most of the time, however, they are an expression of the genetic makeup of the original breeds from which today's breed was bred, which are still included in the breed's gene pool despite the selection being made . Since dominant traits can always be recognized by the phenotype , undesirable coat colors that are based on dominant genes can easily be eliminated by selection through breeding. They do not appear in correct breed breeding. Recessive hereditary factors, on the other hand, which are not phenotypically expressed in heterozygous individuals , that is to say remain “invisible”, can be passed on by carriers , i. H. of animals which outwardly correspond to the breed standard and which are carriers of recessive genes not provided for in the standard. The false color only appears phenotypically when two carriers are paired with each other, so that around 25% of the puppies become homozygous ( Mendel's rules: splitting rule ), i.e. H. unite the recessive genetic information of both parents. For example, in the gene pool of a dog breed, false color genes can be retained for relatively long periods of time, such as white in the German Shepherd and Boxer . In the case of boxers, large white fur brands are permitted in the breed standard, which are caused by the genotype S s ⁱ or S s ^w . As a result, boxers are regularly born extremely white, some with health problems.

By excluding the wrongly colored individuals from breeding, the inheritance of the recessive gene cannot be avoided, because around two thirds of the 75% standard-colored dogs in a litter are carriers again. If only one of the two parent animals is a carrier and the other has the desired genetic disposition homozygous, the recessive false color does not appear in the puppies and thus it remains hidden that a carrier was bred with a carrier and the unwanted gene was passed on.

Biological functions of melanocytes

The pigment cells ( melanocytes ), in which skin and hair pigments are formed, have other important functions in the vertebrate organism , namely in the formation of certain tissues of the peripheral nervous system and the sensory organs for sight and hearing . In the course of embryonic development , the melanocytes formed from precursor cells in the neural crest migrate into various tissues of the developing embryo, both in the internal tissues of the body ( organ systems ) and in the skin and hair roots . This can also be observed in some newborn pups when the initially pink snouts , noses and pads of the paws turn dark after a few days.

There are both disease-causing and harmless variants of the various genes that lead to white fur or white spotting . How they work depends on whether or not they prevent the storage of precursor cells in the organ structures in which they are needed.

Animal welfare relevance

In dogs with false colors, doubts about the racial unity may arise, although in purebred dogs they mostly arise from a splitting of a genetic make-up with a dominant-recessive inheritance or, more rarely, as a result of a gene mutation. In the past, dog breeders were faced with the decision of killing off-color puppies or leaving them with the litter and then giving them away without a pedigree . Today the Animal Welfare Act (Section 17) forbids killing a healthy puppy.

By analyzing the pedigree , one can determine in which breeding lines false color genes are present, provided that the breeders have always given all puppies in the litter reports. In this way the probability of a mating of conductors can be reduced considerably, but not completely excluded.

Today, DNA analysis can provide information about recessive genetic makeup before an animal is used for breeding. In this way, the mating of two animals with undesired genes in the genotype can be avoided. The question of whether and which variants of leucistic genes and albinism genes are found in a dog's genome can also be clarified.

In addition to off-colors that have no impact on health, there are also those who always or at least in certain breeds by pleiotropism associated with malformations or diseases. In such cases there are ethical reasons to forbid the breeding of such dogs (see also Qualzucht ). The following examples have been selected to illustrate the current situation.

Healthy false color dogs

Karakachan in brindle

Shiba Inu : The AKC regards creamy white as a wrong color, the British Kennel Club accepts white with reddish tones (ears).

For example, in the Karakachan , Stromung is considered a false color in the breed standard. No health impairments caused by the color gene are known. In some other breeds, this color is provided as standard.

In Dachshunds , red fur, which is produced either by the Ay allele on the agoutilocus or by the recessive e on the extension locus, is permitted in the standard, although the latter can also occur in puppies of two black and red or syrupy parent animals. In breeds in which only black and red is permitted, the same inheritance phenomenon applies as a reason to classify a single-colored puppy in recessive red or dry leaves as a wrong color.

With the German lace , a single-colored white fur due to the very strong pheomelanin brightening is one of the standard colors. With the Shiba Inu it is considered a wrong color. In the breed standard No. 257 for the Shiba, only red, black and tan, sesame, black sesame and red sesame are provided.

The monochrome white fur has a different genetic cause than that of the white piebald. Like the arctic wolf and the white spitz, it is a monochromatic dog whose hair roots form pheomelanin, but which is extremely lightened by a lightening factor that has not yet been precisely analyzed, which is known as gene i . This is only effective in normal skin, not in the nose, lips, eyelid margins and pads. In dogs with the whitening factor leading to “False White”, the immigration of melanocytes is not hindered, not even in the tissues involved in the development of the sensory organs.

Through breeding knowledge, it is possible to match selection criteria relevant to beauty and health.

In the case of the German Shepherd Dog , white puppies were occasionally born that were not given any papers because of their incorrect color. A separate breed was established from healthy offspring of such false color specimens and entered in the Swiss dog studbook with the name Berger Blanc Suisse ( White Swiss Shepherd Dog ). With him are nose , lips and eye rims black, a sign that the skin melanocytes are present enough and in the skin, the protective pigment melanin is formed. He belongs to the races known as "False White".

For the German Shepherd , white is still considered a false color. Such dogs may not be registered or crossed at Berger Blanc Suisse. In the case of Berger Blanc Suisse, puppies from parent animals that conform to standards can cause undesirable pigment losses. Patchy loss of pigment on the nose, lips and / or eyelid rims are rated as color defects. Disqualifying color defects include complete loss of pigment on the nose, lips and / or eyelid rims or on the skin and balls of the feet, blue eyes and albinism.

Marketing of sick wrong color dogs

An opposite example would be the "White Doberman " in which recessive by albinism are gene nose, lips and eye rims pink, and almost no skin pigments has so these dogs sensitive to the UV component of sunlight are quickly sunburn get a have a greatly increased risk of skin cancer and are prone to other skin diseases. An increased sensitivity of the eyes to light leads to the fact that the animals are blinded in the open air. The white Dobermann is considered a wrong color in Germany for animal welfare reasons, as is the blue. In the blue Doberman and other pinschers, the dilute gene causes a skin disease, the blue dog syndrome . Nevertheless, the White Doberman is offered by "multipliers" at the animal market. In America, active education initiatives have sprung up on the Internet from people who have become owners of double merle dogs as a result of the uncontrolled increase in fodder breeds .

Dealing with problematic genes

Inheritance scheme for the strictly forbidden pairing of two dogs with Merle factor (M = Merle factor available, m = Merle factor not available).

Dog from Merle-Merle mating. One visually impaired and one blind eye. The dog is deaf on both sides . Parents: Australian Shepherd .

The problem is the merle gene , in which the heterozygous dogs are mostly healthy, but the homozygous dogs often have severe malformations. The influence of the merle gene on the coloring is inherited in an incompletely dominant manner. In heterozygous dogs it is usually clearly visible. Only the severe malformations that occur in homozygous dogs are recessive. Despite possible malformations caused by the gene, the Merle staining is permitted in some dog breeds in the breed standard, whereby the heterozygous, healthy dogs are conductors that may not be paired with each other. The wrong color "double merle" is avoided by the breeding regulations, but this does not prevent ignorant "multipliers" outside of the breeding associations from producing around 25%, sometimes seriously, chronically ill puppies with two merle dogs. Dogs with the wrong color "double merle" often have a higher proportion of white in their fur than their parent animals. They have malformations of varying severity in both eyes, are mostly deaf on one or both sides, and often have other developmental disorders resulting from embryonic development. Although pigment cells are formed in them, due to a genetic defect on the silver locus, they lack cytological functions, so that they cannot contribute to the development of healthy organs of vision and hearing. Heterozygous Merle dogs are also sometimes affected by these disorders.

Eye colors

Different colored eyes in a mixed breed dog with Great Dane ancestors .

Also eye colors are defined in the breed standards. Thus, eye colors that deviate from the standard also fall under the term false colors . Blue eyes can occur in dogs due to various genes that affect the color of the coat and eyes and which sometimes cause health problems. Among other things, they arise from the merle gene, which is why they are standard in the dog breeds in which merle is also farmed.

Two blue eyes or iris heterochromia are permitted in the Siberian Husky , but they have a different genetic cause with no effect on coat color and no health disadvantages. Offspring from such matings have healthy sensory organs.

Questionable selection criteria

Dalmatian : wrong color of the eye . An extreme piebald in which almost 10% are deaf on one or both sides.

While in the past there were only conjectures about connections, the advances in molecular genetic research now make it possible to reflect on a scientific basis what should be considered false color and what should be considered permissible color within a breed standard.

For example, Dalmatian puppies are usually born completely white. Puppies that have black or brown spots ( plates ) from birth were excluded from breeding as false colors, although this is a sign that the melanocytes migrate into the body tissue in good time and in sufficient quantities, where they have reached the head Development of important nerve-sensory functions are needed. Dalmatians but also other white-spotted dogs with a lot of white in the head area relatively often suffer from deafness because the melanocytes in the organ structures were missing or not functional. Since these developmental relationships have been researched and known, breeders have begun to rethink the selection criteria. A fully pigmented head has always been prescribed in the breed standard of the German Shorthaired Pointer. No congenital hearing problems arose here.

Another example of a polyphenia of individual color genes in dogs is a defect in the uric acid metabolism of the kidneys , hyperuricosuria. This metabolic disorder, which occurs in Dalmatians, has become a disease typical of the breed due to preferred breeding selection of dogs with pronounced stippling. The specific pattern of the fur is created by combining three genes: a gene for white fur, a dominant gene in the T locus responsible for the stippling and a gene which influences the size of the stippling. The latter is likely to promote the inheritance of the gene responsible for hyperuricosuria ( meiotic drive ).

Basic knowledge from classical genetics

In general, the same applies, as can be seen from the inheritance scheme of the split rule for the false colors, also for all recessive disease-causing genetic traits, namely that sick dogs are born again and again even if the carriers are excluded from breeding, unless the conductors are also excluded from the breed. The Veterinary Association for Animal Welfare advocates measures against torture breeding and hereditary diseases in dogs .

The AKC's molecular genetic laboratory carries out a DNA analysis for registered dogs of any breed at the request of the owner in order to provide clarity about the genotype and to record the results statistically. In Europe, too, in Germany, there are institutes for molecular genetics that carry out DNA analyzes of color genes and other health-related genetic makeup for pets . This enables an effective prezygotic selection.

Characteristic combinations

Inheritance pattern : mating of two carriers of the recessive allele e. The at allele on the agouti locus for the black saddle drawing is only expressed if eumelanin can be stored in the fur.

Example of an inheritance scheme: Both parents ee. One has the recessive Piebald gene sP homozygous, the other is heterozygous with S sP and shows the dominant trait in monochrome phenotype. This mating leads to around 50% piebald and 50% monochrome puppies.

In the Beagle , “tan-white” genotype ee sPsP is permitted in the FCI breed standard.

The color required for the Yorkshire Terrier in FCI Breed Standard No. 86 is Blue and Tan . The dominant allele of the extension locus (E) ensures the formation of eumelanin . The recessive allele e causes a homozygous lack of eumelanin, instead only pheomelanin is formed. If two conductors with Ee are mated who have eumelanin in their fur, according to Mendel's rule of division, an average of 25% homozygous carriers of the allele e are born. With genotype ee the fur is yellow to reddish "tan" (fox-colored) without black. Carriers with the genotype Ee are called gold splitters.

The S gene, which is dominant in dogs, ensures uniform coat coloration. The Piebald gene sP, which is usually recessive in dogs, leads to homozygous white spotting.

There are examples of the sometimes combined occurrence of two false colors ( dihybrid inheritance ) in the Yorkshire Terrier , in which, despite breeding selection, a very rare recessive genetic makeup for white spotting was retained. In addition, there is rarely the genotype Ee. Therefore, puppies are very rarely born who do not produce the eumelanin for the steel-blue saddle prescribed in the FCI breed standard No. 86 ( Golden Yorkshire ).

American breeders had unexpectedly individual only in color not Nonstandard puppies in plain gold, three colors black, white and gold and two-tone white and gold in their litters with it (false color). In 2007 they were registered with the American Kennel Club ( AKC ) under the designation “Parti Color Yorkshire Terrier” ( partially colored) on the grounds that health-related criteria in breed breeding should have a higher priority than the color of the coat. The Biewer Yorkshire Terrier bred in Germany can be traced back to the same carrier of the Piebald gene, through which the first Parti Color Yorkies appeared as false colors in America around the same time. The Biewer Yorkshire Terrier is now considered a separate breed in which the tricolor is mandatory. If conductors of the allele e are mated in three-colored white-spotted dogs , an average of 25% of the offspring are born in two-colored white-gold. In the Biewer Terrier, this is called gold dust .

The same effect also occurs with other three-colored pedigree dogs, for example with the Beagle , in which the two-tone "tan-white" is permitted in the breed standard. In many dog breeds, the breed standard allows a variety of colors, which is conditioned by genes that produce coat colors that are considered false colors in others . For example, with the Longhaired Whippet , all coat colors are permitted, including with ee and white piebald with sP. According to the breed standard, the eyelids should be as dark as possible. Complete pigmentation of the eyelids is desirable. The latter is not only a beauty criterion, but also a health feature. The Labrador Retriever is must be a solid color, according to the breed standard, allowing it to infrequent coat color genotype homozygous fuchsrot ee.

With the genotype ee, caution is advised in all dog breeds in which the merle factor is bred, since in fox-colored dogs the heterozygous presence of the merle factor is phenotypically not or hardly recognizable.

In white piebald dogs and other dogs with possible health problems associated with color genes, a genetic test can determine which genes - there may be several - lead to an individual's color and which recessive genes are also present to check whether there is one that has breeding concerns within the breed.

Accordingly, Mendel's rules usually apply to the inheritance of the individual alleles for the combinations of these and other hereditary factors for pigmentation in all breeds, which are permitted or not depending on the breed standard. With regard to many gene combinations, however, a hierarchy of alleles can be observed ( epistasis ), which makes the situation somewhat more complicated. Since several gene loci always work together ( polygeny ), only experts can adequately understand the inheritance .

Question of breeding approval

Dogs with wrong colors do not receive a pedigree from a VDH affiliated breed association or the pedigree bears the note "excluded from breeding". The breed associations decide whether the conductors are also excluded from breeding . In some associations that have another umbrella organization , the so-called dissidence associations, dogs with wrong colors are allowed to show, provided that they do not cause any health impairment. Their descendants receive their own pedigree. The fact that there are also breeders who breed with false colors for commercial interests and / or ignorance , which are not permitted in the breed standard for animal welfare reasons , cannot be ruled out in principle.

Individual evidence

↑ Anna Laukner: Fellfarben - false colors. Swiss dog magazine 2/07. http://www.feb-ev.de/PDF/fellfarben.pdf

↑ SM dirt, TG Berryere: Genes Affecting coat color and pattern in domestic dogs: a review. In: Anim Genet. 38 (6), 2007 Dec, pp. 539-549. PMID 18052939

↑ Inge Hansen: Inheritance in the dog. Verlag Müller Rüschlikon 2008, ISBN 978-3-275-01652-5

↑ FCI Standard No. 144 German Boxer

↑ Boxer markings

↑ Anna Laukner: Fellfarben - false colors. Swiss dog magazine 2/07. http://www.feb-ev.de/PDF/fellfarben.pdf

↑ Sheila Schmutz 2014: Spots and White Markings

↑ Jens Mathias: Schnauzer breed warden regulations, page 77

^ Hans Räber : Breviary of modern dog breeding, 5th edition, Verlag Paul Haupt Bern - Stuttgart - Vienna, 1995. Page 21

↑ Animal Welfare Act § 17 Paragraph 1 https://www.gesetze-im-internet.de/tierschg/__17.html

↑ Dr. Carmen L. Battaglia: Pedigree Analysis

↑ Veterinary Association for Animal Welfare: Leaflet 141 torture breeding for dogs

↑ Saskia Kristina Hogreve: Studies on the hearing ability ... with special consideration of the iris pigmentation. Institute for Animal Breeding and Pet Genetics at the University of Gießen 2003. ISBN 3-89687-650-3 . Document pages 15–17, PDF pages 29–31. http://geb.uni-giessen.de/geb/volltexte/2003/1332/pdf/HogreveSaskiaKristina-2003-07-07.pdf

↑ Expert group for animal breeding and pet breeding: Expert opinion on the interpretation of Section 11 b of the Animal Welfare Act

↑ Animal Welfare Act § 11 https://www.gesetze-im-internet.de/tierschg/__11b.html

↑ Bernice Bovenkerk, Hanneke J. Nijland The Pedigree Dog Breeding Debate in Ethics and Practice: Beyond Welfare Arguments

↑ Helga Eichelberg Thoughts on contemporary dog breeding

↑ FCI standard No. 257

↑ Japanese Shiba Inu

↑ Karakachan Dog International Association: Karakachan Dog Breed Standard

↑ Silken Windsprite Club: Variety of colors

↑ FCI Breed Standard No. 225 Akita

↑ Stefanie Mahlberg: Genetics of color inheritance In: Der Dachshund 03–05 / 2013

↑ FCI Standard No. 148 Dachshund

^ DTK Landesverband Rheinland eV Regional association in the German Teckel Club 1888 eV colors of the Teckel

↑ FCI Standard No. 97 German lace, including Keeshond and Pomeranian

↑ Anna Laukner: The coat color in the Spitz Swiss dog magazine 1/12 .

↑ FCI Standard No. 257 Shiba

↑ Jess Chappell: Dog Coat Color Genetics: Spotting / false white http://www.doggenetics.co.uk/white.htm#piebald

↑ Anna Laukner: coat color and behavior. Swiss dog magazine: http://hundemagazin.ch/fellfarben-und-lösungen/

↑ Genetics of coat colors in dogs - modifier genes

↑ Hans Räber: Encyclopedia of Rassehunde, Volume 1, Franckh-Kosmos Verlag, Stuttgart 1993/2001. ISBN 3-440-06555-3 . Page 218–222

↑ Breed standard White Swiss Shepherd http://www.weisse-schaeferhunde-zuchtverband.de/html/rassestandard.html