# Laminitis in Horses: Preventing Founder and Shoeing Adjustments ## Key Takeaways - Laminitis is a complex syndrome triggered by systemic or local factors, often involving vascular and inflammatory alterations within the equine foot, leading to compromised lamellar attachment and potential pedal bone displacement (founder). - Endocrine and metabolic causes, particularly Insulin Dysregulation (ID) and Pituitary Pars Intermedia Dysfunction (PPID), are the most common triggers, often exacerbated by high non-structural carbohydrate (NSC) intake from pasture, especially in spring and autumn. - Corticosteroid use, particularly systemic dexamethasone and intra-articular triamcinolone acetonide, poses a significant risk for inducing hyperinsulinemia and laminitis, necessitating careful metabolic risk assessment prior to administration. - Diagnostic imaging, primarily radiography, is essential for assessing pedal bone position and guiding therapeutic farriery, while advanced imaging like venography or PET may be used to evaluate perfusion deficits in chronic cases. - Therapeutic farriery, including achieving a target palmar angle of 3-10 degrees and potentially surgical intervention such as deep digital flexor tenotomy (DDFT), is critical for managing chronic laminitis by realigning the distal phalanx and reducing the pull of the deep digital flexor tendon. - Prevention hinges on identifying at-risk horses (obese, cresty neck, PPID-affected) and implementing strict dietary management (pasture restriction, low-NSC forage) and controlled exercise, alongside judicious corticosteroid use. --- **Immediate owner triage summary:** If your horse shows a bounding digital pulse, a stiff or "pottery" gait, a reluctance to turn, excessive time lying down, or heat in the hooves, treat it as a potential medical emergency. Remove access to lush pasture immediately, place the horse on a deep, soft surface such as sand or shavings, and contact your veterinarian or veterinary surgeon without delay. Do not administer any medication without veterinary direction. Early intervention within the first 24 to 48 hours significantly influences the outcome. Laminitis is a painful and potentially life-threatening condition that requires prompt professional assessment. ## At a Glance: Key Decisions in Laminitis Management | Aspect | Recommendation | Source Basis | |--|--|--| | **Immediate action** | Remove from pasture, deep bedding, call veterinarian | Standard emergency care | | **Pasture access** | Use grazing muzzles for insulin-dysregulated horses to reduce insulin response | [1] | | **Dietary focus** | Monitor pasture non-structural carbohydrates (NSC), especially in spring and autumn | [2], [3] | | **Corticosteroid caution** | Assess metabolic risk before intra-articular or systemic steroid use | [4], [5], [6] | | **Shoeing goal** | Achieve a palmar angle of 3 to 10 degrees in chronic cases | [7] | | **Surgical option** | Deep digital flexor tenotomy (DDFT) for refractory chronic laminitis | [8], [7] | | **Prognostic imaging** | Radiographs are essential; consider advanced imaging for perfusion deficits | [9], [10] | ## Understanding Laminitis and Founder Laminitis is a complex, painful condition affecting the digital lamellae, the interlocking tissues that suspend the distal phalanx (the pedal bone or third phalanx) within the hoof capsule. When these lamellae become inflamed and compromised, the connection weakens. In severe or chronic cases, the pedal bone can rotate or sink within the hoof, a condition known as "founder." This displacement is a structural failure that carries a guarded prognosis. The disease is not a single entity but a syndrome triggered by various systemic and local factors. It is characterized by severe vascular and inflammatory alterations within the equine foot [11]. Understanding the underlying cause in an individual horse is critical for effective treatment and prevention. ## Anatomy and Physiology: Why the Hoof Fails The equine foot is a marvel of biomechanical engineering. The distal phalanx is attached to the inner surface of the hoof wall by hundreds of primary and secondary lamellae. This connection bears the immense forces of weight-bearing and locomotion. In laminitis, a cascade of events disrupts this attachment. Research using positron emission tomography (PET) has shown that even in healthy standing horses, continuous weight-bearing without movement can create discrete regions of reduced perfusion, particularly in the medial sole and lamellae [10]. This suggests that blood flow within the foot is highly sensitive to load and movement. In a horse with laminitis, this compromised perfusion can worsen the ischemic injury to the lamellae. The deep digital flexor tendon (DDFT) exerts a constant pull on the caudal aspect of the distal phalanx. When the lamellar attachment fails, this unopposed pull is the primary force that causes the pedal bone to rotate, with the toe rotating downward and the palmar/plantar aspect pulling upward. This biomechanical understanding underpins many of the therapeutic and shoeing strategies used to manage the disease. ## Causes and Risk Factors Laminitis is often described as a "two-hit" disease, where a primary trigger sets off a systemic inflammatory or metabolic response that secondarily affects the foot. Several distinct causes are recognized. ### Endocrine and Metabolic Causes (The Most Common) The most common triggers are endocrinopathies, specifically: 1. **Insulin Dysregulation (ID) and Equine Metabolic Syndrome (EMS):** These conditions are characterized by an excessive insulin response to dietary sugars and starches. This hyperinsulinemia is a direct trigger for laminitis. Management focuses on reducing the insulin spike. 2. **Pituitary Pars Intermedia Dysfunction (PPID or Cushing's Disease):** This condition is common in older horses and is independently associated with hyperinsulinemia-associated laminitis [12]. Horses with PPID experience more medical events in their lifetime, including laminitis [12]. ### Dietary and Pasture Causes - **High Non-Structural Carbohydrates (NSC):** Access to lush pasture, especially during spring and autumn, is a major risk factor. The concentration of water-soluble carbohydrates (WSC) in pasture can be very high in May and lower in October [2]. Starch concentrations also fluctuate seasonally [2]. - **Forage Quality:** Even in traditional, low-input management systems, the natural variation in forage quality can significantly influence metabolic regulation. Horses consuming carbohydrate-rich forages exhibit higher insulin and leptin concentrations, which are accompanied by elevated body condition and cresty neck scores [3]. ### Inflammatory and Septic Causes - **Grain Overload:** Excessive consumption of grain or concentrates can lead to rapid fermentation in the hindgut, causing endotoxemia and systemic inflammation. - **Retained Placenta / Metritis:** In mares, a severe uterine infection can trigger laminitis. - **Severe Colic / Systemic Illness:** Any severe systemic inflammatory response can be a trigger. ### Corticosteroid-Induced Laminitis Corticosteroids are a known risk factor for inducing hyperinsulinemia and laminitis, particularly in horses with underlying metabolic issues. - A study on dexamethasone, a systemic corticosteroid, showed it can increase insulin levels by an average of 11.5-fold in healthy horses [4]. Pretreatment levels of adiponectin and the leptin-to-adiponectin ratio were useful predictors for the severity of this hyperinsulinemia [4]. - The risk is not limited to systemic use. Intra-articular (IA) triamcinolone acetonide (TA), a common joint injection, also causes a significant insulin spike in some horses [5]. A study found that the maximum plasma insulin concentration (Cmax) after IA TA was 40.2 µIU/mL with placebo but only 16.7 µIU/mL when the horse was also given ertugliflozin, a medication that helps reduce hyperinsulinemia [5]. - However, not all corticosteroids carry the same risk. A study found that intra-articular methylprednisolone acetate (MPA) at a total dose of 80 mg did not induce significant hyperinsulinemia or hyperglycemia in metabolically normal horses [6]. This highlights that the choice of corticosteroid and the metabolic status of the horse are critical considerations. ### Other Risk Factors - **Age:** Older horses are at higher risk. A study on chronic laminitis found that the risk of developing complications with the third phalanx increased by 16% for each year of age [8]. Laminitis is also a leading musculoskeletal cause of death in aged horses [13]. - **Body Condition:** Obesity and regional adiposity (a cresty neck) are significant risk factors for insulin dysregulation and subsequent laminitis [3]. ## Veterinary Examination and Diagnostics A prompt and thorough veterinary examination is essential. The diagnosis of laminitis is based on clinical signs, physical examination, and diagnostic imaging. ### Clinical Signs - **Lameness:** Ranging from a mild, stiff gait to a complete refusal to move. - **Increased Digital Pulses:** A bounding pulse felt at the fetlock or pastern. - **Heat in the Hoof:** The hoof wall may feel warm to the touch. - **Pottery Gait:** The horse takes short, stilted steps, landing on its heels to avoid putting pressure on the painful toe. - **Reluctance to Turn:** Turning places additional stress on the lamellae. - **Increased Time Lying Down:** The horse may be reluctant to stand. - **"Sawhorse" Stance:** In severe cases, the horse may rock back on its heels with its hind legs placed further underneath its body to shift weight off its painful front toes. ### Diagnostic Imaging - **Radiography (X-rays):** This is the cornerstone of diagnosing and monitoring laminitis. Radiographs allow the veterinarian to assess the position of the distal phalanx within the hoof capsule, measure the degree of rotation or sinking, and evaluate for other changes. Research is ongoing to refine diagnostic thresholds. A 2026 study used advanced statistical methods (NURBS-based ROC smoothing) to improve the consistency and reliability of radiographic threshold selection for diagnosing laminitis [9]. - **Venography:** This involves injecting contrast dye into the digital veins to assess blood flow to the foot. It is often used to evaluate the severity of vascular compromise, especially in chronic cases [7]. - **Positron Emission Tomography (PET):** Advanced imaging like 18F-FDG PET can reveal detailed information about tissue perfusion and metabolism. Research using this technique has shown that continuous weight-bearing alone can create perfusion deficits in healthy feet, which has implications for understanding how load contributes to laminitis pathology [10]. ## Evidence-Based Management and Treatment The management of laminitis is multifaceted and must be tailored to the individual horse, the underlying cause, and the severity of the condition. ### 1. Addressing the Primary Cause - **Dietary Restriction:** For horses with metabolic laminitis, the primary goal is to reduce insulin levels. This involves removing the horse from pasture and feeding a low-NSC diet. The seasonal dynamics of pasture NSC are critical; levels are highest in spring and lower in autumn [2]. - **Grazing Muzzles:** For horses that must be turned out, grazing muzzles are a proven tool. A study found that using grazing muzzles in insulin-dysregulated horses significantly reduced their peak insulin response to pasture compared to unmuzzled controls (24.31 µIU/mL vs 45.59 µIU/mL) [1]. This demonstrates that muzzles are effective at reducing the insulinemic response during turnout. - **Managing PPID:** Horses with PPID require specific medical management for that condition, which will in turn help manage their laminitis risk [12]. - **Corticosteroid Avoidance:** In horses at high risk, corticosteroids should be used with extreme caution. If a joint injection is necessary, the veterinarian may consider the type of steroid. While triamcinolone is a common cause of insulin spikes [5], methylprednisolone acetate did not induce hyperinsulinemia in metabolically normal horses in one study [6]. The decision must be made on a case-by-case basis, considering the horse's metabolic status. ### 2. Medical Therapy - **Anti-Inflammatories:** Non-steroidal anti-inflammatory drugs (NSAIDs) are the mainstay for pain relief and reducing inflammation. They are a standard part of postoperative and acute management [7]. - **Medications for Hyperinsulinemia:** For horses with severe insulin dysregulation, medications like ertugliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, are being used. A study showed that ertugliflozin significantly lowered the insulin spike following intra-articular triamcinolone administration [5]. This represents a promising avenue for preventing steroid-induced laminitis. ### 3. Shoeing Adjustments and Therapeutic Farriery Proper farriery is arguably the most critical component of managing chronic laminitis and founder. The goals are to: - **Realign the distal phalanx within the hoof capsule.** - **Support the caudal (heel) aspect of the foot.** - **Reduce the pull of the deep digital flexor tendon (DDFT).** - **Provide comfort and improve mobility.** #### The Role of the Deep Digital Flexor Tendon (DDFT) The DDFT is a major contributor to the biomechanical forces that cause rotation. Several strategies aim to reduce its effect. - **Deep Digital Flexor Tenotomy (DDFT):** This surgical procedure involves cutting the deep digital flexor tendon to relieve the pull on the distal phalanx. It is considered a salvage procedure for chronic, refractory laminitis. - A large retrospective study on DDFT found that it provided pain relief and clinical comfort in horses with chronic laminitis [8]. The study emphasized that patient selection is critical, as outcomes can be inconsistent. The risk of complications with the third phalanx increases with age [8]. - A more recent study combined high-metacarpal DDFT with a specific shoeing protocol (Steward clogs) for horses and ponies with severe refractory laminitis [7]. The results showed a 100% survival rate at 6 months in horses and 88% in ponies. At 24 months, 43% of horses and 50% of ponies survived, with one returning to light work [7]. Target palmar angles (3 to 10 degrees) were achieved in all limbs [7]. This study highlights the potential for a combined surgical and farriery approach. - **Botulinum Toxin Injection:** A less invasive approach is the injection of botulinum toxin into the deep digital flexor muscle. A study in healthy horses showed that this transiently reduced the peak ground reaction force at the toe and shifted the center of pressure palmarly (backward) [14]. This biomechanical effect would be expected to reduce mechanical stress on the dorsal lamellae, suggesting it could be a useful treatment for acute laminitis [14]. The effect was shown to last for at least 7 days but was no longer significant by 14 days [14]. #### Therapeutic Shoeing Principles The specific shoeing approach will depend on the severity of rotation and the individual horse's conformation. - **Stabilization and Support:** The primary goal is to provide a stable, supportive base. This often involves a shoe that extends backward to support the heels and protect the sole. - **Heel Support:** Raising the heels (increasing the palmar angle) reduces the tension on the DDFT and shifts weight-bearing from the toe to the more caudal structures of the foot. The target palmar angle in one study was 3 to 10 degrees [7]. - **Steward Clogs:** These are a type of therapeutic shoe that is glued onto the hoof. They provide excellent support and can be used in conjunction with surgical procedures like DDFT [7]. They are often used in chronic cases to allow the horse to be comfortable while the foot heals. - **Corrective Trimming:** The trim is designed to restore the normal relationship between the distal phalanx and the ground. This may involve removing excess heel or toe to derotate the pedal bone. **Important:** All shoeing adjustments must be performed by a qualified farrier in close consultation with the attending veterinarian. Regular radiographic monitoring is needed to assess the response to treatment and guide further adjustments. ## Unsafe Home Remedies and What to Avoid - **Do not administer any human pain medication** (e.g., ibuprofen, acetaminophen) as these are highly toxic to horses. - **Do not apply topical treatments to the hoof** without veterinary guidance, as some can be caustic or interfere with healing. - **Do not force the horse to move.** Strict stall rest on a deep, soft surface is essential. - **Avoid cold hosing or icing the feet without veterinary instruction.** While sometimes recommended in the acute phase, it is not universally beneficial and may cause discomfort. - **Do not use "hoof testers" or apply pressure to the sole** to test for pain, as this can cause unnecessary suffering. ## Prevention: A Proactive Approach Preventing laminitis is far more effective than treating it. The key is to identify at-risk horses and manage them accordingly. ### 1. Identify At-Risk Horses - **Body Condition Scoring (BCS):** Regularly assess your horse's body condition. A BCS of 6 or higher (on a 9-point scale) is a risk factor. Cresty neck scoring (CNS) is also important; a high CNS is a strong indicator of insulin dysregulation [3]. - **Metabolic Testing:** For horses with risk factors (obesity, previous laminitis, PPID), ask your veterinarian about testing for insulin dysregulation. This can involve a simple resting insulin and glucose test or a more dynamic oral sugar test. - **Monitor for PPID:** Older horses (over 15 years) should be monitored for signs of PPID, such as a long, curly coat that fails to shed, increased thirst and urination, and recurrent infections. ### 2. Dietary Management - **Pasture Restriction:** Limit grazing time for at-risk horses. The highest risk times are the spring (when WSC is highest) and after a frost. A grazing muzzle is an effective tool to reduce intake while still allowing turnout [1]. - **Low-NSC Diet:** Feed a diet based on mature hay that has been tested for NSC content. Soaking hay can further reduce its sugar content. Avoid feeds high in starch and sugar, such as sweet feeds and grains. - **Forage Analysis:** As shown in a study of traditionally managed horses, forage quality varies and directly impacts metabolic health [3]. Testing your hay is a worthwhile investment. ### 3. Exercise - **Consistent, Controlled Exercise:** Regular daily exercise helps with weight loss and improves insulin sensitivity. However, if a horse has had laminitis, exercise must be carefully managed to avoid excessive loading of the compromised feet. ### 4. Corticosteroid Use - **Risk Assessment:** Before any corticosteroid injection (especially triamcinolone), your veterinarian should assess the horse's metabolic status. This may involve testing insulin and glucose levels. In high-risk horses, alternative treatments should be considered, or the use of a medication like ertugliflozin might be discussed to mitigate the insulin spike [5]. ## Prognosis and Long-Term Outlook The prognosis for laminitis varies widely and depends on the cause, severity, and speed of treatment. - **Acute Laminitis:** With prompt and aggressive treatment, many horses with mild to moderate laminitis can recover and return to their previous level of work. - **Chronic Laminitis with Founder:** The prognosis becomes more guarded when there is significant rotation or sinking of the pedal bone. However, with meticulous farriery and management, many horses can live comfortable lives as pasture ornaments. The study combining DDFT with Steward clogs showed that survival at 24 months was 43% for horses and 50% for ponies, with one returning to light work [7]. - **Age as a Prognostic Indicator:** Age is a significant factor. Older horses have a higher risk of complications after DDFT surgery [8]. - **Quality of Life:** The primary goal is to achieve a pain-free, comfortable state. Euthanasia is a humane option for horses that do not respond to treatment and remain in unmanageable pain. Laminitis is a leading musculoskeletal cause of death in aged horses [13]. ## Limitations and When to Contact a Veterinarian This article provides a comprehensive overview of laminitis, but it cannot replace professional veterinary advice. The information presented is based on recent research and clinical guidelines, but every horse is an individual. **Breed-level information cannot predict individual outcomes.** While some breeds are more prone to metabolic issues, any horse can develop laminitis. The specific response to treatment, the severity of the condition, and the presence of other health problems will all influence the prognosis for your horse. **Contact your veterinarian immediately if you observe:** - **Any sign of lameness**, especially if it is bilateral (affecting both front or both hind feet). - **A strong, bounding digital pulse.** - **Heat in the hooves.** - **A reluctance to move or turn.** - **A "sawhorse" stance.** - **Any change in gait after a known trigger** (e.g., grain overload, illness, or a corticosteroid injection). Early intervention is the single most important factor in improving the outcome for a horse with laminitis. Do not wait to see if the horse gets better on its own. ## Frequently Asked Questions ### 1. What is the difference between laminitis and founder? Laminitis is the acute inflammation of the sensitive laminae inside the hoof. Founder is the chronic, structural consequence of severe laminitis, where the pedal bone rotates or sinks within the hoof capsule. ### 2. Can a horse fully recover from laminitis? Yes, many horses with mild to moderate laminitis can fully recover with prompt treatment. However, horses with severe founder may have permanent changes to their hoof structure and may require lifelong therapeutic farriery and management. ### 3. How quickly does laminitis develop after a trigger? The onset can be rapid, often within 24 to 48 hours after a trigger such as grain overload or a severe illness. For metabolic causes, it can develop more insidiously over days or weeks. ### 4. Is grass really that bad for laminitic horses? Yes, lush grass high in non-structural carbohydrates (NSC) is a major trigger for laminitis, especially in horses with insulin dysregulation. The NSC content is highest in spring and autumn, making these the highest-risk times [2]. ### 5. What is a "palmar angle" and why is it important? The palmar angle is the angle of the distal phalanx relative to the ground. In chronic laminitis, the goal of shoeing is often to achieve a target palmar angle (e.g., 3 to 10 degrees) to reduce the pull of the deep digital flexor tendon and improve comfort [7]. ### 6. Are joint injections dangerous for laminitis-prone horses? Some intra-articular corticosteroids, like triamcinolone, can cause a significant spike in insulin, which is a risk factor for laminitis [5]. However, other options like methylprednisolone acetate may not carry the same risk in metabolically normal horses [6]. Your veterinarian should always assess your horse's metabolic risk before any joint injection. ### 7. What is a deep digital flexor tenotomy (DDFT)? A DDFT is a surgical procedure where the deep digital flexor tendon is cut. This releases the pull on the pedal bone and is used as a salvage procedure for horses with severe, chronic laminitis that is unresponsive to other treatments [8], [7]. ### 8. How can I prevent laminitis in my horse? The most effective prevention is to manage risk factors: maintain a healthy body condition, restrict pasture access for at-risk horses (using a grazing muzzle if needed), feed a low-NSC diet, provide regular exercise, and work with your veterinarian to monitor for and manage conditions like PPID and insulin dysregulation. ## Sources [1] [Short-Term Effects of Grazing Muzzles on Insulin in Horses with Insulin Dysregulation out at Pasture.](https://pubmed.ncbi.nlm.nih.gov/42456998/) [2] [The Effect of Seasonal Changes in Non-Structural Carbohydrates in Pasture on the Metabolic Profile of Horses with Laminitis.](https://pubmed.ncbi.nlm.nih.gov/41594457/) [3] [Forage Carbohydrate Profiles and Endocrine Morphometric Interactions in Traditionally Managed Horses from Romania.](https://pubmed.ncbi.nlm.nih.gov/41302145/) [4] [Serum adipokines are useful for predicting hyperinsulinemia secondary to corticosteroid treatment in horses.](https://pubmed.ncbi.nlm.nih.gov/42276125/) [5] [Ertugliflozin decreases the insulin spike in non-insulin dysregulated standardbred horses following intra-articular triamcinolone administration.](https://pubmed.ncbi.nlm.nih.gov/42056832/) [6] [Intra-articular methylprednisolone acetate does not induce hyperinsulinemia or hyperglycemia in metabolically normal horses.](https://pubmed.ncbi.nlm.nih.gov/41370924/) [7] [High-metacarpal deep digital flexor tenotomy and Steward clog shoeing for managing chronic refractory laminitis: A retrospective clinical study.](https://pubmed.ncbi.nlm.nih.gov/41392305/) [8] [Deep digital flexor tenotomy provides pain relief and clinical comfort in horses with chronic laminitis.](https://pubmed.ncbi.nlm.nih.gov/41985510/) [9] [Diagnostic Threshold Identification for Equine Laminitis Using Smoothed Receiver Operating Characteristic Analysis.](https://pubmed.ncbi.nlm.nih.gov/41947533/) [10] [Positron emission tomography using 18F-fluorodeoxyglucose reveals digital perfusion deficits associated with continuous weight-bearing in healthy standing horses.](https://pubmed.ncbi.nlm.nih.gov/41135568/) [11] [Cyclooxygenase-2 and von Willebrand factor-an immunohistochemical study of the equine foot with and without laminitis, post-mortem perfused with paraffin oil.](https://pubmed.ncbi.nlm.nih.gov/41473106/) [12] [Horses diagnosed with pituitary pars intermedia dysfunction do not have shorter life expectancies but experience more medical events during their lifetime.](https://pubmed.ncbi.nlm.nih.gov/41406612/) [13] [Main causes of death in aged horses in a retirement facility in California can be attributed to the digestive and musculoskeletal systems.](https://pubmed.ncbi.nlm.nih.gov/41855668/) [14] [The effect of botulinum toxin injection into the deep digital flexor muscle on foot biomechanics in healthy horses.](https://pubmed.ncbi.nlm.nih.gov/41747387/) [15] [Risk factors for strangulating lipoma obstruction and lipomata in horses.](https://pubmed.ncbi.nlm.nih.gov/41045447/) ## Related Clinical & Scientific Guides * [Equine Hematologic Disorders: Anemia and Coagulopathies](/knowledge/veterinary-medicine/equine-care/equine-hematologic-disorders-anemia-coagulopathies) * [Equine Lifespan: Factors Influencing Longevity in Horses](/knowledge/veterinary-medicine/equine-care/equine-lifespan-factors-influencing-longevity-in-horses) * [Miniature Horse Care Guide](/knowledge/veterinary-medicine/equine-care/miniature-horse-care)