Horse Talk Reads: Spring Grass Laminitis: Prevention, Symptoms, and Management for Healthy Hooves

By Kyla Szemplinski, MS with UT TSU Shelby County Extension

Prevent spring grass laminitis in horses with expert tips on pasture management, symptoms to watch for, and effective treatment options.

All horse owners look forward to a warm, sunny spring following a grueling winter. The days are longer and the grass is becoming lush for grazing, providing fresh nutrients for horses. However, while this nutrient-rich spring grass is beneficial, it can also present challenges—most notably, spring grass laminitis. Laminitis in horses, especially during spring when pastures are at their greenest, is a condition no owner wants to face. This issue not only affects hoof health in horses but can also lead to long-term consequences if not managed properly. While the damage from spring grass laminitis can sometimes be managed, prevention through proper management steps is the best way to protect your horse's hoof health and overall well-being.

What is Laminitis?

Laminitis is a hoof condition in which the laminae become inflamed. The laminae work similarly to Velcro, as they attach the coffin bone to the inside of the hoof wall. When the laminae become inflamed, the coffin bone can sink or rotate within the hoof capsule. Once rotation occurs, the bone's attachment to the hoof wall is permanently disrupted.

Too Much of a Good Thing

Fresh spring grass contains nutrients horses need to meet their requirements. However, it can also present lush spring grass risks, as it often contains a high amount of nonstructural carbohydrates (NSC) in grass, including sugars and starches. When a horse consumes this lush grass, the additional starches and sugars ferment in the horse's gastrointestinal tract. This can overwhelm the microflora population in the GI tract, causing some of the population to die. These microflorae release their endotoxins into the GI tract, affecting the pH balance. The pH imbalance will cause blood flow to be redirected from the hooves to the hindgut to correct this imbalance. Without blood in the laminae, the tissue starts to die, which causes the coffin bone to rotate.

Nonstructural Carbohydrate Content of Grasses

When grasses are first blooming, they are packed with easily digestible and absorbable nonstructural carbohydrates (NSC) in grass. Understanding these lush spring grass risks is important for horse owners, as many factors will affect NSC content, including:

• Type of plant
• Soil composition
• Fertilizer
• Duration and intensity of sunlight
• Time of day
• Season and cutting
• Environmental stressors
• Grass height

Cool-season grasses like timothy, fescue, and orchardgrass, as well as warm-season grasses like bermudagrass and bahiagrass, are typically high in nonstructural carbohydrates (NSC). Understanding the nonstructural carbohydrates (NSC) in grass is essential for recognizing lush spring grass risks. As the morning progresses, NSC levels increase, peaking in the afternoon hours and then decreasing during the nighttime. Maturity is also a major factor affecting NSC content. As the plant matures, it shifts to structural carbohydrates such as cellulose, hemicellulose, and lignin, which are more difficult for the horse's GI tract to break down. Environmental stressors that restrict growth also increase NSCs—when growth is limited, the plant stores energy produced by photosynthesis as a reserve rather than using it to grow.

Symptoms of Spring Grass Laminitis

Before laminitis develops, you might notice your horse gaining weight rapidly. Common symptoms of laminitis and signs of laminitis caused by spring grass include:

• Reluctance to move
• Lameness and shortened stride
• Heat in hooves
• Increased digital pulse
• Stretched white line
• Frequent hoof abscesses
• Dish-shaped appearance on affected hooves
• Hoof rings

Treatment for Spring Grass Laminitis

There is no cure for laminitis, only management that can lessen the pain. When considering treatment for laminitis, the first step for horses with spring grass laminitis is to remove them from pasture immediately and contact your veterinarian. Depending on how severe the laminitis is, your horse may require extended stall rest with the potential for hand-walking. In addition to veterinary care, managing horse pastures to avoid laminitis in the future is essential. Other treatment options include:

• NSAIDs
• Diet and management steps
• Therapeutic farriery: heart-bar shoes and other types of corrective shoeing can help alleviate pain

Preventing Spring Grass Laminitis

Prevention is key when you want to avoid spring grass laminitis. Preventing laminitis starts with proactive spring pasture management and careful attention to your horse's daily routine. Owners can take the following precautions to reduce the possibility:

• Manage pastures: Make sure pastures are not stressed by overgrazing. Always do a pasture and soil analysis every three years.
• Choose turnout times carefully: Turn horses out early in the morning or late at night when NSC levels are low.
• Introduce dietary changes slowly: Whether it is a new hay or grain, allow a week of transition so your horse's gut can adjust.
• Limit turnout: When grass is lush and your horses have been cooped up all winter on hay, start with 15 minutes of turnout on day one. Then, increase by 15 minutes every other day.

Conclusions

Prevention is the critical step to avoid the serious consequences of spring grass laminitis. This condition can develop quickly when horses consume lush spring pasture grass and can result in severe pain and long-term hoof damage. Protecting hoof health in horses means staying vigilant for symptoms and practicing thorough spring pasture management. If left untreated, spring grass laminitis can lead to founder and potentially life-changing outcomes for your horse. If you suspect your horse may be at risk for developing spring grass laminitis, consult with your horse's care team about a management plan that supports both prevention and optimal hoof health in horses.

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