A Guide to DNA Tests for Horses

YourDNA cares about your life and everything that touches it, including your animals. Whether it's dogs or horses, DNA can give you valuable information.

That's why we are taking the time to research how DNA testing is changing the world of horse ownership, so you don't have to.

Quick Overview

Though DNA tests are commonly used to determine parenthood and bloodlines for people, they can be used for animals as well.

A DNA test for a horse can help determine parentage. Owners and breeders may want to determine just which horses in their herd have created the foal.

It may even be necessary for breeders to prove the genetics of a stallion or mare that's going to be used for breeding. A full guide to DNA tests for horses will help you understand the importance, the process, and other necessary details.

How DNA Tests for Horses Work

A DNA test done for horses compares samples in a lab. The sample is most often hair from the horse’s mane.

The DNA profiles of the mother, foal, and potential father are all analyzed carefully to determine true parenthood. It offers insight into characteristics of a horse potentially passed down by one or both of its parents.

There are 23 DNA markers that the test examines to get these answers.

How to Pull Horse Hair for DNA Testing

Not just any hair can get pulled for DNA testing. The process needs to be completed carefully so a valid sample is taken.

The hair sample needs to be pulled above the withers on the mane. Cutting is not an option because the part that is needed for testing is the actual hair follicle. This is where the DNA is contained.

The process may be different for foals. Young horses have much finer hair follicles that may break easier as you pull them.

The tail will provide a better sample in this case. In all instances, it is important to grab roughly 20-30 hairs, or however many your testing agency recommends, so there is enough to be adequately tested. Several may be broken or damaged so having plenty of others available will be necessary.

Genetic Testing Options for Horses

Using a horse’s hair is the most common option, but it is not the only one.

It is also possible to perform genetic testing with a blood sample collection ¹ and even semen. Hair is the most easily accessible which is why it is the typical choice for most breeders and horse owners.

If you would like to try other options, you should consult with your horses’ veterinarian to ensure the proper tools and process is used to get an accurate sample to send in.

Do All Horses Have a Unique DNA Profile?

If you’re wondering if all horses have a unique DNA profile, the answer is yes.

All creatures have their own unique DNA that needs to be examined carefully in order to obtain vital information regarding the identifiers that form its genetic makeup. The horse genome project utilized millions of dollars to create a database of DNA pairs that can be used by scientists to determine both behaviors and physical differences in horses.

This project found that horses have 31 autosomes and 2 sex chromosomes.

What You Can Learn from a DNA Test for Horses

There is a lot to learn from a horse DNA test. If you simply want to know which horse is the sire of your foal, then you can learn that easily by submitting a DNA sample of each the foal, sire, and mare.

The results will be compared to determine if your stallion is in fact that young horse’s father.

The possible ancestral DNA of a horse can also be identified. The results will typically give you up to three possible breeds that are part of your horse’s ancestry.

This test is provided through Texas A&M University. The details are possible thanks to the genome project and the 50 most common breeds tested throughout North America.

If you want to know if your horse has the speed gene ², such as before deciding to use your horse for racing, then that information can also be discovered. The 7 color genes can also be determined through DNA testing.

All genes of the horse are examined and identified during testing if you choose to have a full DNA profile completed and not just parentage or ancestry.

Color Genes

The 7 color genes provide a lot of insight into your horse. Gene W indicates a horse unable to form pigment.

The horse may be born very pale in color for both its skin and mane. This is often seen as an albino horse, but is otherwise considered a white horse.

Gene G is similar, although the color of the horse will not quite be as pale ³. White horses often have this gene. They are not albino because they still have pigment in their skin. It is their hair only that lacks pigmentation.

Gene E denotes black hair pigment. If the entire body of the horse, as well as its mane, is black, then it may have this gene.

Gene A offers distribution of black pigmented hair. There may be some black hair on the horse, such as the mane, but the rest of the horse will be another color, like brown.

Gene C includes a pigment dilution. A horse may have a red pigment that gets diluted to more of a yellow color hue, for example.

The final two options are Gene D and Gene TO. Gene D causes a dun pattern and pigment dilution. A horse may appear splotchy. There might be areas of one color with other spots of a different, lighter color.

A horse with the Gene TO has a Tobiano spotting pattern. These spots are white in color and are much more easily distinguished as spots than those horses with the Gene D.

Most horses have some variation of these genes, making a full DNA workup important for looking at all gene types included.

The Benefits of DNA Testing in Horses

Not only does a DNA test provide insight into the father of the foal in question, but it also provides an ID for your horse.

If one of your herd were to ever get lost or stolen you would have a DNA profile verifying the horse is yours. A profile then taken from the horse you believe to be your lost or stolen prize could be compared to verify if he or she does in fact belong to you.

Medical information is another major benefit of DNA testing. This is particularly true if you get a five-panel test done. You get to see just which underlying medical conditions your horse may have that could be passed to its offspring.

It allows breeders to determine which horses to breed and which to avoid breeding. It also allows you to undergo preventative measures that will help your herd maintain its health ⁴.

How Accurate are DNA Tests for Horses?

DNA tests for horses, just like DNA tests for people, are never 100% accurate.

They do, however, offer a high accuracy rate as long as the horse is not of a mixed breed. Many laboratories that now conduct these tests offer a 99.9% accuracy thanks to upgraded technology and the abundance of information regarding DNA and genetic profiles of various horse breeds.

It does, however, seem to be more difficult to pinpoint the results for a mixed breed than it does for a purebred horse. These tests are typically more precise than the DNA tests for a dog because the horse family does not have as many breeds as the dog family does.

They have also remained fairly pure in their bloodlines and have not been mixed extensively.

Horse DNA Testing Results Explained

The results shown will vary depending on the type of test you have completed.

If you sent in hairs for a simple DNA test to determine parentage, you should see the results between the sire (father), dam (mother), and foal (child).

A typical DNA test that shows genotyping will have a list of genetic markers. VHL20, HTG4, and ASB2 are just a few of the markers you may see listed.

Each of these will have a number associated with it. This tells of the horse’s genetic makeup and helps to determine a number of factors, from color to potential of carrying certain diseases to other identifying characteristics seen both physically and behaviorally with the horse.

A foal often has similar numbers to one of its parents in many of the categories.

A test to determine breeding possibilities for stallions requires five panels. This shows GBED, HERDA, HYPP, MH, and PSSM.

This five-panel test can be taken in combination with the average DNA test through the AQHA.

GBED

Glycogen Branching Enzyme Deficiency indicates a mutation in the GBE1 gene. This disease prevents the glycogen branching enzyme from functioning correctly ⁵.

The liver, brain, and cardiac muscle are all impacted. They will not be able to store glycogen or utilize it adequately. This causes severe muscle weakness and even early death.

A horse with this condition should not be bred because their offspring have a high potential to have it and be stillborn before birth. Most that do survive do not live past four months of age.

HYPP

Hyperkalemic Periodic Paralysis is caused by a mutation found in the sodium channel gene. Typical electrical impulses that allow the muscles to contract do not work correctly in horses with this gene ⁶.

Muscle tremors are the beginning of symptoms, with the possibility of paralysis closely followed. A horse with HYPP may collapse and die at any time.

HERDA

Hereditary Equine Regional Dermal Asthenia is most commonly found in Quarter horses. The Paint and Appaloosa may be affected as well if they were bred with a Quarter horse.

Both the male and female horses would have to possess this gene to create an offspring who possesses it. HERDA affects the skin. It causes lesions, scarring, and may even leave large, open wounds.

MH

Malignant hyperthermia can be caused by stress or the use of certain anesthetics and muscle relaxants. Rigid muscles, shallow breathing, abnormal heart rhythms, and excessive sweating are just a few of the beginning symptoms ⁷.

This is one of the more manageable problems a horse can face. A diet free from fermentable fiber, fat, and starch will be a significant help.

PSSM

Polysaccharide Storage Myopathy is caused by yet another mutation. It is found among the most breeds of horses, with at least 20 breeds able to experience this problem.

Due to an unregulated glycogen flow, excessive amounts of sugar are present in the cells of the muscles. This causes stiffness, pain, and severe weakness. ⁸

Where to Buy a DNA Test for Horses

The best bet would be to speak to a veterinarian about DNA testing.

He or she may offer testing or know of a facility that does.

Otherwise, there are lots of equine test kit options available online, as well as companies who handle the testing. Home test kits require horse hairs to be taped to a sample sheet and sent into a lab with accompanying information.

How Much Does it Cost to DNA Test a Horse?

The price of DNA testing can vary greatly. It depends on where the kit is purchased and which lab you are sending it to.

However, an average cost seems to be around $40 per sample. You can either purchase a parentage verification or get a full DNA profile, or both.

Buying both will cost double the money. The five-panel test and DNA report from the AQHA will cost around $145 for every horse.

Is DNA Testing Right for Your Horse?

When asking yourself if DNA testing is right for your horse, you need to determine how detailed you are in your record keeping.

If you keep detailed records of your herd and are certain of which foal belongs to which parents, you may decide against taking the time for a DNA test. If, however, you have any uncertainty about your horses, a DNA test may give you peace of mind.

It also provides you with insight into your herd when obtaining the DNA profile of each horse you own. Consider the decision carefully before determining if the process is right for you and your horse or horses.

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