DNA Test

Dilution seems to occur from time to time in most breeds of dog. It is unclear whether this is because it is a common mutation or because it occurred very early in the domestication of the dog (or both!). It certainly seems to occur in most (if not all) breed types. I have been studying canine DNA for 30 years and I am still learning and evolving.

Geneticists and breeders have long been aware of several locations of chromosomes (loci), which are responsible for the colour patterns we see in dogs. Each locus has 2 sides. Every puppy inherits one copy of each locus from Mum and one of each from Dad. This is true of all genetic traits. Each of these loci is responsible for one or more traits, either independently, or in conjunction with another locus. The simple rendition below can be applied to any single loci, such as the B loci.

Below I have written a brief description of the colours in general that are available when we test the DNA in dogs.

Agouti – recessive black. DNA would be atat, ayat, or ayay

Allele – one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome, ie, dilute has 2 alleles, D and d.

Black & Tan – minimal white only on the chest. Body is solid black with tan markings on the eyebrows, cheeks, front chest, legs and under the tail.

Black Base – this would be a dog with full black at agouti, ie atat, and a full or carrier at dominant black, ie KN or KK when the dominant black is expressed as Seal. This black base is needed in order to produce true, vivid colours in lue of these colors in fawn or sable. In black base dogs, the genes that change colour affect the coat and not just the nose, eyeliner, pad colour. Note: Seal base may be muted and not vivid.

Black Brindle – black and fawn stripes with or without white markings in any design. Brindle dogs carry at least one Kbr gene and are always either ayay, or ayat at agouti. Brindled bodied dogs cannot have a Kb gene nor be atat.

Black Brindle Merle and Black Merle – black merle with or without white in any design with the added K gene being Brindle. Diluted hair appears blue. Patches, nose, footpads and eyeliner is black. Note: these dogs can appear only brindle, only merle, or a combination of the two.

Black Merle Tri – black, tan, and white in any pattern with random diluted patches. Body is black merle and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Patches, nose, footpads, and eyeliner is black. Note: The black merle or tan will not show where the dog is white but will be black merle tri genetically.

Black Platinum – a white dog with little (10% or less) or no patches of black on the fur. This dog will DNA atat or K, with K being Seal (see Dominant Black).

Black Seal – black or black and white in any design. This dog will DNA as K, with the K being Seal.

Black Tri – black, tan, and white in any pattern. Body is black and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: The black or tan will not show where the dog is white but will be black tri genetically.

Black Trindle – black, trindle and white in any pattern. The tan portions on the dog will be brindled, thus called Trindle. Body is black and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: The black or tan will not show where the dog is white but will be black trindle genetically.

Brown – brown hair colour on a dog called chocolate and sometimes liver.

Blue & Tan – blue and tan with minimal white only on the chest. Body is solid blue with tan markings on the eyebrows, cheeks, front chest, legs and under the tail.

Blue Brindle – blue and fawn stripes with or without white markings in any design. Brindle dogs carry at least one Kbr gene and are always either ayay, or ayat at agouti. Brindled bodied dogs cannot have a Kb gene nor be atat.

Blue Brindle Merle – blue merle with or without white in any design with the added K gene being brindle. Diluted hair appears lighter blue. Patches, nose, foot pads and eyeliner is blue. Note: these dogs can appear only brindle, only merle, or a combination of the two.

Blue Fawn – fawn colour fur with nose, eyeliner, & foot pads being blue or grey with light to dark tone.

Blue Ghost Merle – fawn/sable colour fur with nose, eyeliner and foot pads being blue or grey with light to dark tone and visible faint merle patches when young. These merle patches fade into the fawn/sable coat and are not visible at adulthood in most instances.

Blue Merle – blue merle with or without white in any design. Diluted hair appears lighter blue. Patches, nose, foot pads, and eyeliner is blue.

Blue Merle Tri – blue, tan and white in any pattern with random diluted patches. Body is blue merle and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Diluted hair appears lighter blue. Patches, nose, foot pads, and eyeliner is blue. Note: The blue merle or tan will not show where the dog is white but will be blue merle tri genetically.

Blue Platinum – A white dog with little (10% or less) or no patches of blue on the fur. This dog will DNA as dd.

Blue Sable – A dog with fawn coloured hair, sometimes with blue tips. Blue etching is often seen around the eyes, throughout the coat, on the tail and feet. The pigment on the nose, pads and eyeliner will be blue. Some of these dogs will show tan points. It is not known why the tan points can bleed through on some Sables and not on others.

Blue Seal – blue or blue and white in any design. This dog will DNA as dd K, with the K being Seal.

Blue Tri – blue, tan and white in any pattern. Body is blue and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: The blue or tan will not show where the dog is white but will be blue tri genetically.

Blue Trindle – blue, trindle and white in any pattern. The tan portions on the dog will be brindled, thus called Trindle. Body is blue and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: The blue or tan will not show where the dog is white but will be blue trindle genetically.

Carrier – every gene has 2 sides. When one side is positive and one side is negative, then the dog is considered a carrier of that trait, whether it be colour, pattern, disease etc a carrier dog will pass on the carrier gene at a rate of 50% on each individual puppy born.

Chocolate and Tan – chocolate and tan with minimal white only on the chest. Body is solid chocolate with tan markings on the eyebrows, cheeks, front chest, legs and under the tail.

Chocolate Fawn – chocolate and fawn stripes with or without white markings in any design. Brindle dogs carry at least one Kbr gene and are always either ayay, or ayat at agouti. Brindled bodied dogs cannot have a Kb gene nor be atat.

Chocolate Brindle Merle – chocolate merle with or without white in any design with the added K gene being brindle. Diluted hair appears lighter chocolate. Patches, nose, foot pads and eyeliner is chocolate. Note: these dogs can appear only brindle, only merle or a combination of the two.

Chocolate Fawn – fawn colour fur with nose, eyeliner and foot pads being chocolate with light to dark tone.

Chocolate Ghost Merle – fawn/sable colour fur with nose, eyeliner and foot pads being chocolate with light to dark tone and visible faint merle patches when young. These merle patches fade into the fawn/sable coat and are not visible at adulthood in most instances.

Chocolate Merle – chocolate merle with or without white in any design. Diluted hair appears lighter chocolate. Patches, nose, foot pads and eyeliner is chocolate.

Chocolate Merle Tri – chocolate, tan and white in any pattern with random diluted patches. Body is chocolate merle and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Patches, nose, foot pads and eyeliner is chocolate. Note: The chocolate merle or tan will not show where the dog is white but will be chocolate merle tri genetically.

Chocolate Platinum – a white dog with little (10% or less) or no patches of chocolate on the fur. This dog will DNA as bb.

Chocolate Sable – a dog with fawn coloured hair, sometimes with chocolate tips. Chocolate etching is often seen around the eyes, throughout the coat, on the tail, and feet. The pigment on the nose, pads and eyeliner will be chocolate. Some of these dogs will show tan points. It is not known why the tan points can bleed through on some sables and not on others.

Chocolate Seal – chocolate or chocolate and white in any design. This dog will DNA as bb K with the K being Seal.

Chocolate Tri – chocolate, tan and white in any pattern. Body is chocolate and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: The chocolate or tan will not show where the dog is white but will be chocolate tri genetically.

Chocolate Trindle – chocolate, trindle and white in any pattern. The tan portions on the dog will be brindled, thus called Trindle. Body is chocolate and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: The chocolate or tan will not show where the dog is white but will be chocolate trindle genetically.

Clear Sable – a sable dog with no dark hairs in its coat. Clear sables are almost indistinguishable from recessive reds. Note: Clear sable can hide merle as effectively as recessive red, although this is not the case 100% of the time.

Cryptic Merle – cryptic merle is a scientific term used for the merle gene with a shorter poly-a tail. This term is incorrectly used to define a Phantom or Ghost Merle which usually has the longer poly-a tail but is not present on the dog for lack of black base. Cryptic merle should only be used when the merle dog has been identified with DNA – a positive Mc gene.

Dilute – a gene that dilutes black coat colour in dogs to grey or blue. Dilute dogs will DNA as dd.

Dominant Black – a gene that can produce black seal or brindle. The seal or brindle has to be determined visually.

Double Merle – a dog with full merle (MM). Double merles are predominantly white. The merle patches tend to be on the upper body. They may or may not have the spotting gene. Sometimes double merles or double dapples are 100% white. You must never breed this type of genetics.

Fawn – a dog with fawn coloured hair that can vary from almost white to darker shades of fawn, red, orange etc.

Full – every gene has 2 sides. When both sides are positive, the dog is considered a Full or Double for that trait, whether it be colour, pattern, disease etc. A Full Trait dog will pass on one copy of that trait to every puppy born.

Full Suited – any colour and tan with no white or minimal white only on the chest.

Genotype – a dogs genotype is its complete heritable genetic identity, however, the word genotype can also refer just to a particular gene or set of genes carried by an individual dog.

Phenotype – This is the physical appearance of the dog.

Ghost Merle – synonymous with the term Phantom Merle. A merle dog without a black base, that is not visibly merle. The merle gene only visibly affects a black based dog, thus the term ghost merle. *** Note: this is not to be confused with cryptic merle, which is a scientific term used for the merle gene with a shorter poly-a tail.

Lethal White/Double Dapple – Double merles are often referred to as “lethal whites”. This is totally incorrect term as lethal white is a completely separate gene that does not occur in dogs, but in horses. The merle gene is not lethal, however it can be problematic if doubled in some breeds, for example the double dapple in dachshunds.

Lilac & Tan – lilac and tan with minimal white only on the chest. Body is solid lilac with tan markings on the eyebrows, cheeks, front chest, legs and under the tail.

Lilac Brindle – lilac and fawn stripes with or without white markings in any design. Brindle dogs carry at least one Kbr gene and are always either ayay, or ayat at agouti. Brindled bodied dogs cannot have a Kb gene nor be atat.

Lilac Brindle Merle – lilac merle with or without white in any design with the added K gene being brindle. Diluted hair appears lilac or almost white. Patches, nose, foot pads and eyeliner is lilac. Note: these dogs can appear only brindle, only merle, or a combo of the two.

Lilac Fawn – fawn colour fur with nose, eyeliner, & foot pads being lilac or grey with light to dark tone.

Lilac Ghost Merle – fawn/sable colour fur with nose, eyeliner, & foot pads being lilac or grey with light to dark tone and visible faint merle patches when young. These merle patches fade into the fawn/sable coat and are not visible at adulthood in most instances.

Lilac Merle – lilac merle with or without white in any design. Diluted hair appears lighter lilac. Patches, nose, foot pads and eyeliner is lilac.

Lilac Merle Tri – lilac, tan and white in any pattern with random diluted patches. Body is lilac merle and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Patches, nose, foot pads, and eyeliner is lilac. Note: The lilac merle or tan will not show where the dog is white but will be lilac merle tri genetically.

Lilac Platinum – a white dog with little (10% or less) or no patches of lilac on the fur. This dog will DNA as bb dd ee.

Lilac Sable – a dog with fawn coloured hair, sometimes with lilac tips. Lilac etching is often seen around the eyes, throughout the coat, on the tail and feet. The pigment on the nose, pads, and eyeliner will be lilac. Some of these dogs will show tan points. It is not known why the tan points can bleed through on some sables and not on others.

Lilac Seal – lilac or lilac and white in any design. This dog will DNA as bb dd K, with the K being seal.

Lilac Tri – lilac, tan, and white in any pattern. Body is lilac and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: the lilac or tan will not show where the dog is white but will be lilac tri genetically.

Lilac Trindle – lilac, trindle and white in any pattern. The tan portions on the dog will be brindled, thus called Trindle. Body is lilac and white with tan markings on the eyebrows, cheeks, front chest, legs and under the tail. Note: the lilac or tan will not show where the dog is white but will be lilac trindle genetically.

Merle – this gene produces dogs with irregularly shaped patches of diluted pigment and solid colour in the fur. The patches can have jagged edges and can be small dots to very large patches of fur. The diluted parts of the fur are a lighter version of the original fur colour.

Non-Carrier – every gene has 2 sides. When both sides are negative, the dog is considered a non carrier for that trait, whether it be colour, pattern, disease etc. A non-carrier dog will never pass on that trait to any puppy born.

Patchwork Merle – a merle dog with different colour spots in the coat. The merle gene is unstable and can sometimes partially dilute some of the patches in the coat, which would be somewhere between the base coat colour and the patch colour. They may sometimes appear brownish. This term is synonymous with the term “Tweed Merle”.

Phantom Merle – synonymous with the term ghost merle. A merle dog without a black base, that is not visibly merle. The merle gene only visibly affects a black based dog, thus the term phantom merle. Note: this is not to be confused with cryptic merle, which is a scientific term used for the merle gene with a shorter poly-a tail.

Piebald – a white spotting pattern that does not have a uniform genetic basis. Some white patterns are symmetrical, some are not and some dogs are all white. ***see White Platinum – A white dog with little (10% or less) or no patches of colour on the fur.

Sable – A dog with fawn coloured hair sometimes with black tips. Black etching is often seen around the eyes, throughout the coat, on the tail, and feet. Some of these dogs will show tan points. It is not known why the tan points can bleed through on some sables and not on others.

Tan Point – Doberman/Rottweiler type tan markings that appear on the eyebrows, sides of cheeks, lower legs, front chest and under the tail. If the dog is white in these areas or is a Seal, the tan points will not show but will be hidden. The terms “Tan Point” and “Tri” are interchangeable.

TRI – The dog must carry 2 copies of [atat] to be a Tri. Depicts that a dog has tan points/markings. Also indicates the dog would DNA as [atat] at agouti, even if the tan points are hidden. This term was originally meant to indicate 3 colours on a dog, but so many people use the term to indicate the tan markings – Doberman type – that to hold down confusion, this is the official way we use it now.

Triple Carrier – a person could argue that any dog is a triple carrier since there are upward of 13 colour genes and modifiers. For the purpose of this write up the term Triple Carrier denotes the DNA of the dog, specifically a dog that carries at least one blue (d), one chocolate (b) and one tan (at), no matter what the colour of the dog.

Tweed Merle – a merle dog with different colour spots in the coat. The merle gene is unstable and can sometimes partially dilute some of the patches in the coat which would be somewhere between the base coat color and the patch color. They may sometimes appear brownish. This term is synonymous with the term “Tweed Merle”.

Variants – one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome, ie, dilute has 2 alleles – D and d. ***see Allele