Reduce Risk in Your Equine Breeding Program With Genetic Testing

Successful breeding programs are built on risk management. Genetic testing allows breeders to identify hidden disease risks before breeding season begins — helping prevent non-viable foals, avoidable losses, and long-term damage to a program’s reputation.

Why Genetic Risk Matters

Many serious equine genetic diseases are recessive or inherited silently, meaning healthy-appearing horses can still produce affected foals when paired incorrectly.

Studies across multiple breeds show that 5–15% of horses may carry at least one known genetic disease mutation, depending on breed and population. Without testing, these risks remain invisible until a foal born and/or lost.

When carriers are identified and managed properly, breeders can eliminate the risk of producing affected foals without removing quality horses from breeding programs.

Common & Potentially Lethal Genetic Diseases in Horses

Genetic testing helps screen for health conditions such as:

• GBED (Glycogen Branching Enzyme Deficiency): Causes late-term abortion, stillbirth, or death shortly after birth. Affected foals are always fatal. Commonly found in quarter horse, paint horse, Stock breeds & related breeds.
• HYPP (Hyperkalemic Periodic Paralysis): Causes muscle tremors, paralysis, and in severe cases sudden death. Dominant inheritance means even one copy poses 25% risk. Commonly found in quarter horse, paint horse, and Stock breeds.
• WNVR (Warmblood Night Vision Retinopathy): Causes congenital night blindness, impacting safety, usability, and long-term value. Observed across several breed groups.
• PSSM1 (Polysaccharide Storage Myopathy Type 1): Leads to muscle pain, tying-up episodes, poor performance, and chronic management challenges. Commonly found in quarter horse, paint horse, Stock Horses, Warmbloods, Draft breeds.
• LWO / OLWS (Lethal White Overo Syndrome): Affected foals are born unable to pass manure and die or are euthanized within days. Occurs only from carrier-to-carrier matings. Commonly found in paint horse & stock horse breeds.
• WFFS (Warmblood Fragile Foal Syndrome): Causes extreme skin fragility; foals are usually stillborn or euthanized shortly after birth. Carrier rates reported around 9–11% in some populations. Commonly observed in warmblood breeds, but can appear in other breeds as well.

Screen for these risks and 50+ more with the Pro Package 2.0

How Genetic Testing Reduces Breeding Risk

By testing breeding stock, breeders can:

• Avoid carrier-to-carrier or high-risk matings (P.S. Have your horses tested? Try our free Build-A-Horse tool!)
• Increase live foal and viability rates
• Reduce emotional and financial losses
• Provide transparency and confidence to buyers
• Protect the long-term integrity of bloodlines

Genetic testing does not limit breeding, it guides smarter breeding.

Genetic testing is one of the most effective tools breeders have to reduce risk before breeding season begins. Identifying genetic disease risks early helps ensure healthier foals, stronger programs, and better outcomes long-term.

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