🦠 Leptospirosis in Horses Vet Guide 2025 by Dr Duncan Houston

Welcome to this in-depth veterinary guide on leptospirosis in horses, penned by Dr Duncan Houston BVSc. Leptospirosis is a zoonotic bacterial infection affecting horses and humans, causing signs such as fever, uveitis, abortion, and kidney disease. I'll guide you through everything you need to know—from recognition and diagnosis to treatment, vaccination, and prevention. 🐎✨

📌 What Is Equine Leptospirosis?

Leptospirosis is caused by spirochete bacteria of the genus *Leptospira*, particularly *L. interrogans* serovar Pomona in North America. It spreads via the urine of wildlife (e.g., rodents, skunks, deer), contaminating water or feed that horses ingest or contact through mucous membranes or wounds :contentReference[oaicite:3]{index=3}.

📋 Common Clinical Signs

• Fever, lethargy, anorexia
• Equine recurrent uveitis—painful inflamed eyes, tearful discharge, cloudiness :contentReference[oaicite:4]{index=4}.
• Abortion or stillbirths in pregnant mares :contentReference[oaicite:5]{index=5}.
• Renal failure—blood in urine, increased drinking, and urination :contentReference[oaicite:6]{index=6}.

🔍 How Is It Diagnosed?

Diagnosis includes:

• Serology—MAT to detect antibodies :contentReference[oaicite:7]{index=7}.
• PCR on blood, urine, or fetal fluids :contentReference[oaicite:8]{index=8}.
• Culture is definitive but impractical due to slow growth :contentReference[oaicite:9]{index=9}.

Testing is recommended in horses with uveitis, abortions, unexplained fever, or renal signs.

💊 Treatment & Management

Leptospirosis is treatable with antibiotics and supportive care:

• Penicillin or tetracyclines (e.g., doxycycline) to clear infection :contentReference[oaicite:10]{index=10}.
• Enrofloxacin can be used in certain cases :contentReference[oaicite:11]{index=11}.
• In uveitis cases, topical corticosteroids or intravitreal gentamicin may be used :contentReference[oaicite:12]{index=12}.
• Supportive care: fluids, NSAIDs, renal support, and abortion case isolation for 14–16 weeks :contentReference[oaicite:13]{index=13}.

With prompt treatment, clearance is likely, although chronic uveitis may require lifelong monitoring.

🛡️ Vaccination & Prevention Strategies

Prevention includes both vaccination and farm-level measures:

• A vaccine targeting *L. interrogans* serovar Pomona is available for horses ≥ 6 months, especially useful on breeding farms :contentReference[oaicite:14]{index=14}.
• Remove stagnant water sources and clean water/feed containers regularly :contentReference[oaicite:15]{index=15}.
• Exclude wildlife and rodents, control pests, and keep feed areas clean :contentReference[oaicite:16]{index=16}.
• Isolate symptomatic mares (abortions or uveitis) and monitor urinary shedding status :contentReference[oaicite:17]{index=17}.

📊 Quick Reference Table

📝 Case Action Plan for Owners & Vets

• Monitor horses with signs like eye issues, fever, abortion, or kidney disease.
• Collect blood/urine samples for MAT and PCR before starting antibiotics.
• Begin appropriate treatment and supportive care promptly.
• Isolate mares with abortions or recurrent uveitis; consider urinary culture.
• Implement farm-level hygiene and rodent/wildlife control.
• Vaccinate in endemic settings and use biosecurity for herd protection.
• Follow-up: recheck serology and monitor renal/ocular function.

🔚 Final Thoughts

Leptospirosis in horses is treatable and preventable. With recognition of key symptoms, accurate testing, timely antibiotic and supportive care, and robust vaccination plus biosecurity, this zoonotic disease can be controlled effectively. If you need help implementing protocols—diagnostics, uveitis management, vaccination planning—our **Ask A Vet** team is ready to assist. Download the Ask A Vet app for 24/7 expert equine advice and support. 🌟