Breeding and raising horses involves a mix of science and passion. Genetic testing has become an essential tool for horse owners and breeders, offering a window into a horse’s DNA and the potential to improve equine health, performance, and breeding practices. Understanding equine genetic testing panels is key to making informed decisions for your horse’s future.
What Is Genetic Testing for Horses?
Genetic testing analyzes a horse’s DNA to identify specific genetic mutations that could impact their health, performance, or breeding potential. By identifying these traits, owners can mitigate risks, avoid breeding combinations that could produce affected offspring, and select horses with the ideal characteristics for their discipline.
Horse genetic testing panels are groups of tests bundled together to screen for multiple genetic disorders or traits in one evaluation. These panels are particularly important for breeding decisions, as they help ensure that foals are healthy and free from inheritable diseases.
The 6-Panel Genetic Test: A Comprehensive Screening
The 6-panel genetic test is a thorough evaluation used to screen horses for seven critical
genetic disorders. A horse that tests N/N (clear of all mutations) for these disorders is ideal for
breeding, which means the horse doesn’t carry the genes for these conditions. Horses that have
one copy of the mutation (N/HRD, N/H, N/G, etc.) are considered carriers of the mutation but
are not clinically affected.Clinically affected horses for these diseases must carry two copies of
the mutated gene (HRD/HRD, H/H, G/G etc.) The disorders typically screened in a 6-panel test
include:
HERDA (Hereditary Equine Regional Dermal Asthenia): A condition causing skin fragility and lesions, particularly problematic in working horses.
PSSM1 (Polysaccharide Storage Myopathy): A muscle disorder that affects performance and can lead to tying up.
GBED (Glycogen Branching Enzyme Deficiency): A fatal disorder in foals caused by improper glycogen storage.
HYPP (Hyperkalemic Periodic Paralysis): A muscle condition leading to tremors, paralysis, or respiratory issues.
MH (Malignant Hyperthermia): A reaction to anesthesia or stress that can be life-threatening.
MYMH (Myosin-Heavy Chain Myopathy) formerly known as IMM (Immune-Mediated Myositis): A muscle disorder caused by immune system dysfunction.
EJSCA (Equine Juvenile Spinocerebellar Ataxia): A spine disorder that progresses within a few days until affected foals are unable to stand without assistance.
Breeding with a horse that is N/N on this test reduces the likelihood of passing on any of these conditions to offspring, ensuring healthier foals and stronger breeding programs.
While the 6-panel test is required by the AQHA for all stallions, this only tells half the story. The
mare will be responsible for 50% of the genetics, so it is equally important to test her for these
same genetic mutations.
For example, a mare and stallion that are both carriers of GBED (N/GBED) have a 25% chance
of producing a foal with the fatal condition, however, breeding a stallion who is a carrier
(N/GBED) to a mare who is (N/N) eliminates the chance of producing a foal with the fatal
condition. Genetic testing can prevent this by identifying carriers and allowing breeders to
choose pairings that won’t produce affected offspring.
Genetics Is An Evolving Science
Over time new genetic diseases can emerge. One that has been recently discovered is Equine
Juvenile Spinocerebellar Ataxia (EJSCA). Genetic testing is available for this disease but is not
currently required by the AQHA for breeding stallions.
Why Is Genetic Testing Important?
Equine genetic testing panels empower breeders to make informed choices. Testing prevents the transmission of life-threatening or debilitating conditions, improves herd health, and supports the long-term well-being of breeds. Additionally, responsible genetic testing protects the investment and reputation of breeding operations.
Even beyond breeding, knowing your horse’s genetic profile can guide decisions about care, training, and performance expectations. Horses with genetic predispositions to certain conditions, such as PSSM1, may require specialized diets or exercise regimens to thrive.
Choose Valley Equine For Your Equine Reproduction
Equine genetic testing panels are essential for horse owners, breeders, and veterinarians. They help eliminate the guesswork, ensuring that each breeding decision contributes to the health and longevity of future generations. By testing for common genetic disorders, breeders can create healthier horses and uphold the standards of their breeding programs.
At Valley Equine Reproduction, we offer expert advice and services to support your breeding goals, including guidance on genetic testing and providing documentation on every stallion we stand. Ready to make the most informed breeding decisions? Contact us today to learn how we can help you achieve healthy, thriving foals for years to come.
