If you are looking to purchase your first American Paint Horse Association (APHA) or Pinto Horse Association (PtHA) horse or just want to read up on some coat color material, I hope this page is of help to you. I have included information on coat color and coat patterns and a small amount of information on coat genetics and how to get your horse tested. I have also included a link to a great color calculator available that I often use. The cost for most color tests is about $25 and requires only a sample of pulled mane or tail hair with intact roots.
Coat color genetics is very interesting, but remember, you don't ride color! Although, some knowledge of pattern genetics is necessary when breeding paints to avoid situations like the production of a Lethal White Overo (LWO/OLWS) which is discussed towards the bottom of the page.
Jump to what you are looking for:
-Coat color bases (black and red) (black/red factor)
-Black and red punnet squares
-Agouti and how to figure out your horse's black/red factor and agouti genetics
-Coat patterns overview (tobiano, overo, tovero)
-Pattern punnett squares, information on lethal whites (LWO, OWLS)
-How and where to get them tested
-Color chart (genotypes)
***I want to note here, before we get started, that in order for a horse to have any modifier like gray or dilution like cream or dun or other color factor like tobiano, overo, or roan, one of the parents MUST carry that gene. Genes like these do not pop out of nowhere and at least one of the parents MUST have given the offspring the gene; no exceptions. For example, two sorrel horses will not magically produce a gray, palomino, dun, etc. (Actually, two sorrel horses can only produce a sorrel horse) Now, let's get started...
Horses can be broadly classified into two base pigments: Black and Red.
→Horses with a black base pigment mostly have black points. Points are the lower legs, tail, mane, tips of ears, and nose. Examples of these coat colors include black, brown, bay, blue roan, buckskin, grullo, and perlino. The allele (E) represents the black factor and is dominant. Therefore, horses that have black points can be represented by (EE) or (Ee).
Examples of horses with a black base pigment include Black Jack (EE), Dees Miss Peppi (Ee), Miss Poco Buck Swen (Ee), Star, Angel Joe Star Buck (EE), Spark of Faith (Ee), Blondys Blue Bonanza (Ee), and Swen Sparks Fly.
Buckskin (E_A_Crcr) Bay (E_A_Tt) Buckskin (E_AaTt) Black (EEaaTt)
→Horses with a red base pigment have red points. Examples of these coat colors include sorrel (or chestnut), red roan, red dun, palomino, and cremello. The allele (e) represents the red factor and is recessive. Therefore, horses that have red points can be represented by only (ee).
Examples of horses with a red base pigment include Doc Alena Ember (ee), Faiths Calico (ee), Sallys Miss Ziggy (ee), Diamond (ee), Ima Sonny Lil Doc (ee), and Sebastian (ee).
Sorrel (eeA_Tt) Palomino (ee _ _Crcr nO) Sorrel (ee _ _)
»Horses homozygous for the black gene, like Black Jack, are represented by (EE) and will always pass one (E) to offspring. In other words, they will never have red-based offspring.
»Horses homozygous for the red gene, like Roxie, are represented by (ee) and will always pass one (e) to offspring. Skip's offspring can be (ee), red, or (Ee), black, depending on the stud. This recessive allele, (e), can be overridden by the dominant allele, (E), if mated to a horse carrying a (E): (EE) or (Ee).
→These possibilities can be expressed in the form of a simple Punnett Square:
Black Jack (EE) x (EE) Mare
Black Jack (EE) x (Ee) Mare
Black Jack (EE) x (ee) Mare
All crosses produce horses with black points.
Mare (ee) x (ee) Max
Mare (ee) x (Ee) Stallion
Mare (ee) x (EE) Black Jack
Agouti is often listed just after the red/black factor alleles like these examples: EeAA, EEAA, eeAa, eeaa, EEaa, etc. This is because all horses will have genes representing agouti just as they will all have genes representing red/black factor. Agouti is represented by the alleles (A) and (a). (A) is dominant and (a) is recessive. A horse can be (AA), (Aa), or (aa).
On black horses (EE) or (Ee), the dominant agouti (A) limits the expression of black to the horse's points. Black points are seen on buckskins and bays and are those black tips on ears, black mane, black tail, and black lower legs. You need recessive agouti genes (aa) to get a true black horse.
On red horses (ee), the agouti gene is hidden. Your horse may be (AA), (Aa), or (aa), but you wouldn't be able to physically tell that on a red based (ee) horse. To figure out your red based horse's agouti genetics, you will need information on the sire and dam, information on its offspring, or a genetic test.
True black horses are those with (EE) or (Ee) and (aa). My stallion, Sparks Black Jack, is a true black horse and is homozygous recessive for agouti (aa).
Here are some examples:
Black stallion expressing recessive agouti gene (aa).
Note the stallion's body is all black and there is no brown shading in the coat. Black Jack is called a 'true black' horse.
Furthermore, the two base coats can be affected by dilutions and modifiers like Gray (G). Gray is a dominant gene, which means all coats modified by gray (G) will lose pigmentation and eventually turn white in 5 to 10 years. Homozygous (GG) horses will show more rapid graying and larger distribution of gray than heterozygous (Gg) horses, but both will "gray out". (g) is the absence of gray. (gg) horses will not gray out.
Badger, my gray cow horse, is a great example of a gray horse.
Both gray horses and paint horses with pink pigmented skin, have a tendency to develop skin cancer around or after about 10-years-old. A common area subject to skin cancer is the vulvar area or anal area under the horse's tail. A lot of paints especially toveros and tobianos will have pink pigmented skin in this area. Many gray horses will have pink skin, but a lot will have dark pigmented skin with a few lighter pigmented patches.
Test for Gray is ~ $25.
Cream is commonly represented by (Cr). Normal is represented by 'n' or lower case 'cr'. A horse carrying (CrCr), two cream genes, will be more diluted than a horse carrying (nCr) or (Crcr), only one cream gene. (nCr) and (Crcr) are the SAME and are used based on personal preference. (nn) is normal, not dilute.
(CrCr) horses carrying 2 cream genes are represented by cremellos, perlinos, and smoky creams. (nCr) horses carrying only 1 cream gene are represented by palominos, buckskins, and smoky blacks. (nn) horses can be represented by sorrel, black, or bay.
(CrCr) horses (like Swen, the perlino mare pictured below) will always pass one cream gene on to their offspring. For instance, two (CrCr) horses would produce a (CrCr) baby. A (nCr) horse like Max, my '06 APHA palomino overo stallion, or Rio, an AQHA buckskin mare, has a 50% chance to pass a cream gene on to offspring.
Perlinos, cremellos, and smoky creams oftentimes look similar. They all have 2 cream genes and different red/black factor and agouti genetics. People like to call them 'white' horses. They have a very very light color body that is almost white with mostly pink skin, blue eyes, and light colored mane and tail.
(ee _ _ nCr nO) Palomino (E_ A_ nCr) Buckskin (ee _ _ nCr) Palomino
Palominos have a golden color body and a white mane and tail with black skin.
Buckskins have a tan color body and a black mane and tail and black points (ear tips, lower legs, nose, mane, and tail). Buckskins can have countershading and primitive markings like leg barring and partial lines down the croup and back. They also can have frosting (white coloring) on the mane and tail.
Smoky blacks look very similar to black horses and oftentimes cannot be differentiated from black horses.
Cremellos, perlinos, and smoky creams sometimes vary only genetically and cannot be sorted out by physical appearance. In this case, you would test for red (ee) or black (E_) factors and agouti (A_). The palomino has (ee). The buckskin has (E_) and (A_). Her agouti (A) gene causes black points to show.
Cremellos, perlinos, and smoky creams (CrCr) are oftentimes referred to as pink horses.
More examples of perlino horses (carrying 2 cream genes): Angel Joe Star Buck (EEAaCrCr), Miss Poco Buck Swen (EeAaCrCr)
More examples of buckskin horses (carrying 1 cream gene): Dees Miss Peppi (EeA_CrcrDd) and Swen Sparks Fly (E_AaCrcr)
More examples of palomino horses (carrying 1 cream gene): Ima Sonny Lil Doc (ee__Crcr)
Test for Cream is ~ $25.
Dun is commonly represented by (D). A horse carrying (DD) or (Dd) will exhibit similar or same amounts of dun factor. (dd) is normal, not dun.
(DD) and (Dd) cause the body to be diluted; the points are not affected. (DD) and (Dd) horses are represented by buckskin duns, red dun, or grulla.
(DD) and (Dd) have a dorsal stripe and usully leg barring, and/or a shoulder patch.
Red Dun (eeaaDd)
(Dd) Red dun, Kizzy happens to be genetically tested. Her genotype is ee aa Dd. Note that her sorrel coat is diluted to a pinkish red and that she has a dorsal stripe; her points are not affected - they are still sorrel. Also note that since she is aa, recessive agouti, she will produce 100% true black foals with a homozygous black, true black stallion like Black Jack. If these true black foals receive her dun gene (50% chance), they will become grulla.
Examples of horses carrying dun: Sallys Miss Ziggy (eeaaDd), Dees Miss Peppi (EeAaDdCrcr)
Dunskin Mare (E_A_CrcrDd)
Carries both 1 cream gene and 1 dun gene.
She has a dorsal stripe, frosting on the mane and tail, light body color, and leg barring can easily be seen on her front left leg just above the knee. She is Crcr (nCr) and Dd.
Painted horses can be broadly classifieds into 3 basic color patterns: Tobiano, Overo, and Tovero.
→Tobianos usually have distinct characteristics:
Sorrel Tobiano (eeA_Tt) Bay Tobiano (E_A_Tt) Black Tobiano (EEaaTT)
The tobiano trait is dominant and is represented by (T).
→Overos usually have distinct characteristics:
Examples of the overo pattern can be seen on Faiths Calico (eeA_nO).
Palomino Overo (ee_ _Crcr nO) Sorrel Overo (eeA_nO)
»The overo pattern actually consists of 3 separate patterns, which will be discussed further in the genetics section.
→Toveros, as the name implies, are a mixture between the two other patterns:
An example of the tovero pattern can be seen on Spark of Faith (EeAaTtnO).
Black Tovero (E_aaTtnO) Bay Tovero (EeAaTtnO)
If you want to breed for a unique pattern or try to avoid a particular outcome, you need to understand pattern genetics.
»The tobiano pattern is dominant (T) while non-tobiano is recessive (t). This means that if (T) is present in a foal, (TT) or (Tt), the foal's pattern will be tobiano. If a cross yields a (tt) foal, the foal is absent of the tobiano trait and pattern. An example of a (tt) horse is Star.
Most tobianos are heterozygous (Tt), but some, like Black Jack, are homozygous dominant (TT) and will produce painted offspring 100% of the time. Testing for these genes will be covered further down the page. (tt) is said to be homozygous recessive and describes no exp oression of the tobiano gene or pattern.
Black Jack (TT) x (TT) Mare Black Jack (TT) x (Tt) Mare Black Jack (TT) x (tt) Skip
100% Chance of Tobiano Foal
Heterozygous Stud (Tt) x (Tt) Heterozygous Mare
75% Chance of Tobiano Foal
Heterozygous Stud (Tt) x (tt) Skip Homozygous Recessive Stud (tt) x (tt) Skip
50% Chance of Tobiano Foal 0% Chance of Tobiano Foal
»The term overo describes 3 genetically distinct color patterns, but has been lumped together in 1 description through habit and convenience.
The 3 overo color patterns include the frame overo, the splashed white overo, and the sabino pattern.
→The frame overo usually has white patches centered in the body and neck with coloring around them. An example of this can be seen on Faith. The frame overo pattern acts as a dominant gene (nO). Commonly, a frame overo mated to a solid horse will produce 50% painted (nO) offspring. Some frame overos can be almost solid, lacking in spots, and will produce painted offspring 50% of the time. Frame overos can also produce lethal white foals (OO). By mating two frame overos, (nO) x (nO), there is a 25% likelihood a foal can receive both copies of the (O) gene. If a foal receives two copies of the (O) gene, the foal is born white and will die of neural related gut abnormalities. Blood typing and DNA testing can eliminate the possibility of lethal whites by providing the opportunity for responsible breeding plans.
Max (nO) x (nn) Mare Max (nO) x (nO) Missy
50% Chance of Frame Overo Foal 50% Chance of Frame Overo Foal
25% Chance of Lethal White Foal
Since the frame overo pattern (nO) does exhibit dominance, it is helpful in the production of the overo pattern in offspring. The frame overo pattern is very desirable. Breeding between (nO) and (nn) horses is 100% safe. The only reason you need to be worried about lethal whites is if one horse you are breeding is (nO) and the other horse hasn't been tested. In that case, testing the other horse by simple genetic testing can determine if the cross may produce a lethal white. Production of lethal whites is 100% avoidable.
→The sabino pattern describes horses with flecks, patches, and roan areas. These horses usually have blue or partially blue eyes, four white feet and legs, a mostly white head, and a speckled coat. A lot of deviance of these general guidelines occurs. Sabinos can be pretty white and survive unlike lethal whites and are not currently associated with lethal whites.
→Splashed white is the least common coat pattern. Genetic study of the splashed white is even newer than that of the frame overo. Some evidence of deafness seems to be linked to splashed white horses. No homozygous splashed whites have been documented and genetic defects have yet to be linked to this scarcity. Splashed white horses often look like they've been dipped in white paint.
You may choose to have many different DNA tests performed on your horse. DNA testing is simple and cost effective. Several tests include Red/Black Factor (EE or ee), Tobiano Homozygosity (TT), Lethal White Overo (LWO/OLWS), Hyperkalemic Periodic Paralysis (HYPP), and Hereditary Equine Regional Dermal Asthenia (HERDA). In most cases, testing is $25 to $40 a test and requires only a sample of the horse's mane or tail including the hair roots.
- H/H - homozygous dominant HYPP affected horse showing severe symptoms
- N/H - heterozygous HYPP carrier showing minimal symptoms
- N/N - homozygous recessive normal horse with normal genes
- N/N - homozygous dominant normal horse with normal genes
- N/H - heterozygous HERDA carrier with no symptoms
- H/H - homozygous recessive HERDA affected horse showing symptoms
You can visit sites like Pet DNA Services of AZ and Animal Genetics Inc. or shop around for less expensive testing. Click here for a great color calculator from Animal Genetics Inc.! Now that you know your EE's, TT's, and LWO's, you'll be better able to use the information!
If you are thinking about breeding your mare to a (nO) frame overo, you should have your mare tested for the (O) gene. Just because she is an overo does not mean that she will be a carrier, but you must remember that even solid horses can be carriers for the gene. Even though mating (nO) with (nO) only has a 25% of producing a lethal white, anything more than O% should be enough to sway that decision. You should never mate two carriers together.
Why not? Well, what is a lethal white? A lethal white foal is a foal whose intestinal system has not developed proper neural pathways. The foal will be born almost pure white and will die at about 72 hours after its first meal has not been properly digested.
In saying that, it is not a horrible thing to have a carrier. It can be a positive thing as the offspring will be 50% overo and most likely painted. If the dam or sire is (nO), that does not mean that the offspring will be (nO) even if they are painted especially since tobianos can be (nO). Frame overo is a desirable coat pattern especially in riding horses, show horses, and event horses because it is flashy. Careful breeding will create beautiful horses and will avoid lethal whites.
Another important thing to remember is that sometimes your tobiano mare or stallion may be a carrier. Not all (nO) horses are frame overos, much less overos at all. They can be tobianos, and rarely, solid AQHA quarter horses, mini horses, and even thoroughbreds. The overo gene is independent and devoid of the tobiano gene. The tobiano gene may show in your tobiano horse while the overo, (nO), remains hidden phenotypically, or visually.
The two different traits, Tobiano and Overo, may appear on either different loci on the same chromosome or on two different chromosomes:
♂ ♀ or ♂ ♂ ♀ ♀
So, the offspring could end up with (E) and (O). If you tested the horse for the tobiano allele, this might deter you from testing for (O). Tobiano horses and solid horses can still be (nO) and therefore potentially produce lethal whites and should be tested for the LWO trait if breeding with a (nO) stud or mare.
I hope this has helped to either better inform you or to clear up a few things that may have been a little fuzzy. As more research is done on coat color and coat pattern genetics, I am sure things will get much more complicated. What? ...Did you think it would get any easier?
The American Paint Horse Association has some great information on their website in the form of PDF files and can provide you with some great brochure information as well.
In addition, genetic testing web sites have very accurate information.
Q: What color will two sorrels make?
Q: What is the difference between sorrel and chestnut?
A: Sorrel is eeA_ and Chestnut is eeaa; this can be distinguished only by color genetics information of the parents or by testing. It cannot be seen phenotypically.
Q: What is phenotype and genotype?
A: Phenotype describes physical characteristics. This horse looks sorrel. That horse looks cremello.
Genotype describes the actual genetics. This horse is genetically a chestnut, not sorrel, although they look the same (eeaa vs. eeA_). That horse is genetically a perlino, not a cremello although they look the same or similar (E_A_CrCr vs. ee _ _ CrCr).
Q: What is homozygous and how do I know if my horse is homozygous?
A: Homozygous means the horse has two of the same exact type of alleles. For example, my stallion, Sparks Black Jack, is EEaaTT and is therefore triple homozygous for EE, aa, and TT (black, recessive agouti, and tobiano). These are examples of homozygosity: aa, AA, EE, ee, TT, CrCr, DD, GG. If both parents are homozygous, then the offspring is homozygous. It cannot be seen phenotypically and must be determined by information from parents or genetic testing.
Q: What stallion can I use to make a tobiano?
A: You will need to use a homozygous tobiano stallion to guarantee that your foal is tobiano. Otherwise, if your mare is not homozygous (she is heterozygous tobiano or solid) then it is possible to get a solid foal.
Q: What crosses produce a palomino horse?
A: Sorrel x Palomino = 50% sorrel, 50% palomino
Sorrel x Cremello = 100% palomino
Palomino x Palomino = 25% sorrel, 50% palomino, 25% cremello
A heterozygous black horse with cream such as a buckskin, perlino, smoky black, or smoky cream can also be used. Please use a color calculator to test your own crosses.
Q: What offspring result from mating to a gray stallion?
A: If the stallion is homozygous gray, the offspring will be gray. If the stallion is heterozygous gray, then there is only a 50% chance his offspring will be gray given that the mare does not carry the gray gene.
Q: What stallion will always pass dun?
A: A stallion that is homozygous dun. This can be a dunskin, bay dun, grullo, or red dun with DD, homozygous dun.
Q: Can my frame overo horse be homozygous for frame overo?
A: No. Homozygous frame overo, or OO, is lethal. Only nO can exist in a viable foal.
Q: Can a paint horse produce a solid?
A: Yes! A heterozygous paint horse can produce a solid when bred to a solid or ANOTHER heterozygous paint horse. The ONLY way you are guaranteed a paint foal is if ONE or both of the parents is homozygous like my stallion, Sparks Black Jack, who will always produce painted babies. A heterozygous paint horse is a heterozygous tobiano paint (Tt) or a frame overo lwo horse (nO) and etc. Just because your horse is painted does not mean that all of its babies will be, too.
Q: If you breed a solid horse to a homozygous tobiano horse will you get a paint foal?
A: Yes, the offspring is guaranteed to inherit a tobiano gene and will be Tt.
Q: What are the color genetics for _____________?
A: Sorrel is ee _ _; Bay is E_A_; Black is E_aa
Palomino is ee _ _ nCr; Buckskin is E_A_nCr; Smoky Black is E_aanCr
Cremello is ee _ _ CrCr; Perlino is E_ A _ CrCr; Smoky Cream is E_aaCrCr
Red Dun is ee _ _ D_; Bay Dun is E_A_D_; Grullo is E_aaD_
Dunalino is ee _ _ nCrD_; Dunskin is E_A_nCrD_; Smoky Grullo is E_aanCrD_
Gray is _ _ _ _ G_
|GENETIC COLOR CHART (X)||Sorrel Base (ee _ _)||Bay Base(E_A_)|| Black Base (E_aa)|
|1 Cream gene added||Palomino (ee_ _nCr)||Buckskin (E_A_nCr)||Smoky Black (E_aanCr) |
|2 Cream genes added||Cremello (ee_ _CrCr)||Perlino (E_A_CrCr)||Smoky Cream (E_aaCrCr)|
| Dun gene added||Red Dun (ee_ _D_)||Bay Dun (E_A_D_)||Grullo (E_aaD_)|
| Dun gene and 1 cream added||Dunalino (ee_ _nCrD_)|| Dunskin (E_A_nCrD_)||Smoky Grullo (E_aanCrD_)|
| Gray gene added||Gray (ee_ _G_)||Gray (E_A_G_)|| Gray (E_aaG_)|
| Tobiano gene added (T_)||Any color above + Tobiano pattern ||Any color above + Tobiano pattern||Any color above + Tobiano pattern|
|Frame overo gene added (nO)||Any color above + Frame overo pattern||Any color above + Frame overo pattern||Any color above + Frame overo pattern|
|Tobiano (T_) and Frame overo gene added (nO)||Any color above + Tovero pattern||Any color above + Tovero pattern||Any color above + Tovero pattern|
*nCr and Crcr both mean carrying only 1 cream gene. They are interchangeable.
*A (_) denotes that the space can be filled with either a dominant or recessive gene with no change in color.