6 Types of Limb Deformities in Horses and How to Recognize Them

Limb deformities in horses, also known as angular and flexural limb deformities, can significantly impact a horse’s soundness, movement, and long-term health. Some deformities are congenital (present at birth), while others develop as the foal grows. Early recognition and intervention are key to managing these conditions effectively.

While not an exhaustive list, here’s a look at six common limb deformities in horses and how to identify them.

1- Carpal Valgus (Knock Knees)

What it is: A common angular limb deformity where the knees (carpi) deviate outward. It can lead to arthritis and ligament strain, which can create further injuries. Depending on the severity, cases can be improved with farrier and veterinary intervention early in the foal’s life. 

How to recognize it:

• The lower part of the limb angles outward from the knee.
• The horse may stand with its knees closer together than its hooves.
• Often seen in foals but may correct itself as they grow in mild cases.

2- Carpal Varus (Bow-Legged)

What it is: The opposite of carpal valgus, where the knees angle inward. The knee is set to outside of the vertical due the the inward angle of the cannon. These horses are at higher risk of developing osteoarthritis in the fetlock, knee, and pastern.

How to recognize it:

• The horse’s knees appear too far apart, with the lower limb angling inward.
• May lead to excessive strain on the limb.
• Less common than carpal valgus but can cause long-term joint issues.

3- Flexural Deformities (Contracted Tendons)

What it is: A condition where the tendons are too tight, preventing normal extension of the limb. In newborn foals, sometimes light exercise can improve the condition. However, veterinary care should always be sought as soon as it is suspected so appropriate treatment can be applied.

How to recognize it:

• The foal appears to be walking on its toes with its heels off the ground.
• Difficulty standing or nursing in severe cases.
• Can affect the fetlocks, carpus (knee), or coffin joint.

4- Hyperextension (Lax Tendons or "Dropped Fetlocks")

What it is: A condition where the flexor tendons are too loose, causing the fetlocks to sink too low.

How to recognize it:

• The horse stands with its fetlocks almost touching the ground.
• More common in newborn foals
• Often improves with time and controlled exercise, but severe cases may need more intensive, veterinary, supportive care.

5- Rotational Limb Deformities (Toed-In or Toed-Out Stance)

What it is: A twisting of the limb that causes the hooves to turn inward (pigeon-toed) or outward (splay-footed).

How to recognize it:

• The horse’s toes either point inward or outward instead of straight ahead.
• May cause uneven hoof wear and affect movement efficiency.
• Often seen in young foals and can sometimes correct with proper trimming.

6- Angular Limb Deformities of the Fetlock (Windswept Deformity)

What it is: A condition where the limbs appear to lean to one side, often affecting both front or hind legs in opposite directions.

How to recognize it:

• The foal’s legs may appear "swept" in one direction.
• Often present at birth but may improve as the foal grows.
• Severe cases may require medical intervention.

When to Seek Veterinary Care

While some mild limb deformities self-correct as a foal grows, more severe cases require veterinary assessment. Treatment options include corrective trimming, splinting, controlled exercise, nutritional management, and, in some cases, surgery. Early diagnosis and intervention can make a significant difference in long-term soundness.

Understanding these common limb deformities can help horse owners and equine professionals recognise and address potential issues early, ensuring the best possible outcome for the horse’s health and performance.

Resources:

1. The Horse’s Back (THB) (Dr Jane Clothier); All About Crooked Legs: Angular Limb Deformities in Horses and Foals, April 5, 2020
2. Conformation and Limb Deformities in Horses" was published on August 2, 2011, by Dr. Christy Corp-Minamiji, DVM, of Davis, California. Thehorse.com
3. Flexural and Angular Limb Deformities in Foals: Types, Causes & Treatment" written by Dr. Jane Clothier, Ph.D., reviewed by Dr. Emily Gilbert, Ph.D., and underwent veterinary review by Dr. Madison Ricard, DVM, Ph.D., DACVP, PAS. It was published on March 21, 2023, and last updated on October 9, 2024 Madbarn.ca
4. The article "Common Forelimb Conformation Faults in Horses" was written by Kelly Hebner, BSc (Kin), MSc, and published on May 29, 2024.madbarn.ca
5. "Contracted Tendons: Flexural Limb Deformities" by Dr. Jennifer Lugton of Equine Veterinarians Australia (EVA) and published in Hoofbeats Magazine in 2008
6. “Crooked foals part 2 (Flexural limb deformities)” Springhill Equine Vetrinarians, 2021 
7. Percheron Horse Breeders Association of Australia 
8. Veterinary Anomolies, College of Veterinary Medicine,  University of Minnesota 

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