🩺 Epiphysitis in Young Horses: A Vet’s 2025 Guide | Dr Duncan Houston BVSc

Meta description: 🦴 A 2025 vet’s guide by Dr Duncan Houston on epiphysitis (physitis) in foals—recognise, treat, prevent, and monitor growth plate inflammation with expert support.

1. 🧠 What Is Epiphysitis?

Epiphysitis (also called physitis) is an inflammatory condition affecting the growth plates (physes) of young, rapidly growing horses—typically aged 4–8 months, but sometimes up to 2 years. These enlarged and painful physes are seen in distal limbs—like fetlocks, knees, and hocks—when cartilage fails to ossify normally :contentReference[oaicite:3]{index=3}.

2. ⚠️ Why It Happens

Although the exact cause isn’t fully understood, epiphysitis is often linked to:

• Nutritional imbalance: Excess calories or protein with mineral/calc‑phos mismatches :contentReference[oaicite:4]{index=4}
• Rapid growth: High-plane nutrition accelerates ossification burden :contentReference[oaicite:5]{index=5}
• Conformational stress & exercise: Excessive strain on developing physes :contentReference[oaicite:6]{index=6}
• Genetics: Some breeds are predisposed to DODs like physitis :contentReference[oaicite:7]{index=7}
• Infection/trauma: Localized bacterial or physical stress may exacerbate inflammation :contentReference[oaicite:8]{index=8}

3. 🔍 Recognising Clinical Signs

• Swollen, warm physes—hourglass or “boxy” shape on palpation :contentReference[oaicite:9]{index=9}
• Mild to moderate lameness—foal may shift weight or trot stiffly :contentReference[oaicite:10]{index=10}
• Foal may rest affected limb, stand camped-out at rest :contentReference[oaicite:11]{index=11}
• Fever and generalized discomfort are uncommon unless secondary infection occurs

4. 🧪 Diagnosis Methods

• Clinical exam: Visual and manual assessment of joints
• Imaging: X-rays show flared growth plates; ultrasounds can assess soft tissue
• Bloodwork: May be normal, but useful to assess systemic health and mineral status
• History: Diet, growth rate, exercise pattern, conformation reviews

5. 🩺 Treatment Strategies

5.1 Nutrition Adjustment

Scaling back calories and protein while ensuring proper calcium-to-phosphorus ratio (~1.6:1) supports normal ossification :contentReference[oaicite:12]{index=12}. For example:

• Reduce concentrates; shift to quality hay
• Add mineral supplements (dicalcium phosphate, bone flour, vitamin D) if diet is imbalanced :contentReference[oaicite:13]{index=13}

5.2 Controlled Exercise & Rest

Limit high-impact activity during inflammation—stall or small paddock rest is recommended. However, complete inactivity isn’t ideal; controlled movement prevents joint contractures :contentReference[oaicite:14]{index=14}.

5.3 Anti-inflammatory Medications

NSAIDs like meloxicam are preferred for foals due to lower gastric and renal risks. Use under veterinary guidance for 1–2 weeks or until inflammation subsides :contentReference[oaicite:15]{index=15}.

5.4 Corrective Farriery

Frequent trims or supportive shoeing help balance conformation and reduce uneven load on growth plates :contentReference[oaicite:16]{index=16}.

5.5 Treating Infection or Trauma

If physitis is associated with infection, veterinarians may use antibiotics or surgically drain the area :contentReference[oaicite:17]{index=17}.

6. ⭐ Prognosis & Outcomes

• Mild cases usually resolve with management and normal sport development :contentReference[oaicite:18]{index=18}
• Severe cases affecting physes asymmetrically can lead to angular limb deformities and lameness :contentReference[oaicite:19]{index=19}
• Early detection and intervention lead to better outcomes

7. 🛡️ Prevention Tips

• Feed balanced diet tailored to growth stage—avoid overfeeding :contentReference[oaicite:20]{index=20}
• Ensure correct Ca:P ratio and trace minerals
• Balance exercise—allow turnout, avoid high-impact work during growth spurts
• Regular vet checks, farriery, and growth monitoring

8. 💬 Ask A Vet: Support Throughout

• 📸 Upload growth plate photos or videos to assess swelling
• 📋 Customized feeding plan to slow growth safely
• 📆 Reminders for nutrition, trimming, NSAID doses, recheck timing
• 🎓 Webinars on developmental orthopedic diseases and foal nutrition

9. 📆 Timeline & Follow-up

• Inflammation typically subsides in 2–8 weeks
• Once physes close (~18–24 months), condition resolves
• Monitor for angular deformities during healing—refer for orthopedic care if needed

10. 🧩 Case Example

Typical scenario: A 6‑month‑old Warmblood foal on high-energy feed presents with bilateral fetlock swelling and mild lameness. X‑rays confirm flared physes. Diet is reduced, NSAIDs provided, turnout continued in soft paddock. After 6 weeks, swelling resolved and foal continues growing soundly.

11. ❓ FAQs

Can epiphysitis reoccur?

It may relapse if excess feeds or hard work continue during growth plate stress—monitor diet and workload.

Is stall rest always needed?

No—controlled turnout with restricted speed prevents stiffness while avoiding overload.

What supplements help?

Balanced calcium, phosphorus, trace minerals, and vitamin D can support healthy ossification.

When to refer?

Refer severe, asymmetric cases or those with significant deformity or persistent lameness.

12. ✅ Key Takeaways

• Epiphysitis = growth-plate inflammation in young foals
• Recognised by swollen, warm physes and mild lameness
• Managed with diet control, NSAIDs, rest, and regular farriery
• Prevention focuses on balanced nutrition, proper workload, and monitoring growth
• With early care, most foals grow sound and athletic
• Ask A Vet offers personalised care from diagnosis through growth and recovery 💙

🐎 Observed Swollen Joints in Your Foal?

Send photos and feeding data via Ask A Vet. As Dr Duncan Houston, I’ll help assess epiphysitis severity, adjust nutrition and management, plan rechecks, and support healthy growth. Together, we’ll help your foal grow into a strong, sound athlete. 🐴💞