š¦ Leptospirosis in Horses Vet GuideĀ 2025 byāÆDrĀ DuncanĀ Houston
Welcome to this in-depth veterinary guide on leptospirosis in horses, penned by DrĀ DuncanĀ 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 knowāfrom recognition and diagnosis to treatment, vaccination, and prevention. šāØ
š 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}.
š Common Clinical Signs
- Fever, lethargy, anorexia
- Equine recurrent uveitisāpainful inflamed eyes, tearful discharge, cloudiness :contentReference[oaicite:4]{index=4}.
- Abortion or stillbirths in pregnant mares :contentReference[oaicite:5]{index=5}.
- Renal failureāblood in urine, increased drinking, and urination :contentReference[oaicite:6]{index=6}.
š How Is It Diagnosed?
Diagnosis includes:
- SerologyāMAT 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.
š 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 14ā16 weeks :contentReference[oaicite:13]{index=13}.
With prompt treatment, clearance is likely, although chronic uveitis may require lifelong monitoring.
š”ļø Vaccination & Prevention Strategies
Prevention includes both vaccination and farm-level measures:
- A vaccine targeting *L. interrogans* serovar Pomona is available for horses ā„āÆ6 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}.
š Quick Reference Table
| Aspect | Key Points |
|---|---|
| Agent | *Leptospira interrogans*, serovar Pomona |
| Signs | Fever, uveitis, abortion, kidney issues |
| Diagnosis | MAT, PCR, culture (rare) |
| Treatment | Antibiotics + supportive care |
| Vaccination | Pneumonia serovar Pomona vaccine for broodmares/farms |
| Prevention | Water management, wildlife control, isolation |
| Shedding risk | Monitor urine in abortion/uveitis cases |
š 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.
š 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 protocolsādiagnostics, uveitis management, vaccination planningāour **AskāÆAāÆVet** team is ready to assist. Download the AskĀ AāÆVet app for 24/7 expert equine advice and support. š
Ā©āÆ2025 DrĀ DuncanĀ Houston BVSc ā AskāÆAāÆVet Blog Writer
This article is general veterinary education and does not diagnose or treat an individual animal. Always confirm medication names, doses and interactions with the veterinarian who knows your pet.
If your animal is struggling to breathe, collapsed, bleeding heavily, seizing, or has eaten something toxic, contact your vet or the nearest emergency clinic now.
Animal Poisons Helpline (AU) 1300 869 738 Ā· Animal Poisons Helpline (NZ) 0800 869 738 Ā· ASPCA Animal Poison Control (US) (888) 426-4435
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Ask A Vet articles are written by Dr Duncan Houston BVSc, a practising veterinarian, unless another author is named in the byline.
