Genetic Health Testing for Appaloosa Horses

Like any breed, Appaloosa horses, known for their eye-catching spotted coats and versatility, can be predisposed to certain genetic health conditions. While they are typically a fairly hardy breed, Appaloosas may face some genetically linked health conditions more frequently than others. This includes:

Hyperkalemic Periodic Paralysis (HYPP)

While HYPP is most commonly associated with Quarter Horses, some Appaloosas may also carry the gene mutation responsible for this condition due to their shared ancestry. HYPP causes episodes of muscle tremors, weakness, and paralysis due to abnormal sodium channels in muscle cells. Heterozygous horses (HYPP/n) experience more moderate symptoms that can usually be managed through diet and exercise. Homozygous horses (HYPP/HYPP) are much more severely affected, and some breed registries will not accept these animals. Genetic testing is the only way to know for sure if your Appaloosa has HYPP.

Congenital Stationary Night Blindness (CSNB)

CSNB is a recessive disorder caused by Leopard Complex Spotting (LP), also known as Appaloosa spotting. This genetic condition, which occurs when a horse is homozygous for LP (LP/LP), affects the horse's vision, particularly in low-light conditions. Appaloosas with CSNB may have difficulty seeing in dim light or at night. While they can still get along well during the day, their vision may be impaired in certain lighting conditions. Observable coat pattern alone is not necessarily enough to identify CSNB-affected horses, especially those who have minimal patterning, which is why genetic testing is highly recommended to verify a horse’s LP genotype.

Equine Metabolic Syndrome / Laminitis Risk (EMS / LAM)

EMS is a metabolic disorder that can affect horses of any breed, including Appaloosas. EMS is characterized by insulin dysregulation, obesity, and an increased risk of laminitis. Researchers studied horses with severe laminitis caused by EMS and discovered important genetic markers near a gene that might affect how the horses manage cholesterol. Horses with these genetic markers, both hetero- (EMS/n) and homozygous (EMS/EMS), were 9x more likely to develop laminitis secondary to EMS, especially if they were also overweight or obese. This is a genetic health risk, meaning if your horse carries one or two copies of the variant, they are not necessarily destined to develop the disease but it does indicate that they are at a higher risk of developing it.

Equine Recurrent Uveitis Risk and Severity (ERUR / ERUS)

Also known as moon blindness, ERU is a common cause of blindness in horses, including Appaloosas. It is an inflammatory condition that affects the uveal tract of the eye. Symptoms include tearing, squinting, sensitivity to light, and cloudiness of the eye(s). ERU can be managed with medication, but it may eventually lead to blindness in some cases. Our comprehensive ProPanel DNA testing package includes two tests that determine whether your Appaloosa is genetically predisposed to a higher risk of developing ERU (Equine Recurrent Uveitis Risk - ERUR) and if they face an increased risk of ERU symptom severity (Equine Recurrent Uveitis Severity - ERUS). Like EMS, these genetic risk tests cannot determine whether your horse has or will certainly develop ERU, but rather let you know that your horse is at a higher risk of developing ERU and/or developing more severe ERU symptoms.

Do you have an Appaloosa that you would love to learn more about down to their DNA? Check out our Health Panel test which evaluates your horse for all of these health conditions, risk factors, and so much more to get peace of mind today!