11/07/2025
Pigeon Fever, caused by the bacterium Corynebacterium pseudotuberculosis, is a fly-borne disease that’s becoming increasingly common across the U.S. Once mostly seen on the West Coast, it’s now emerging in southern and eastern states.
🔍 How It Spreads:
Flies play a major role in transmission, carrying the bacteria (which originally lives in the soil) from draining abscesses or contaminated soil to other horses. Infection can occur through:
• Flies landing on open wounds or scrapes
• Contact with contaminated dirt or pus
• Direct contact with an infected horse
⚠️ Signs to Watch For:
Pigeon Fever can show up in several ways:
1️⃣ External Abscesses (most common)
• Swelling, often on the chest or belly (“pigeon breast” look)
• Abscesses that rupture or drain thick pus
2️⃣ Internal Abscesses on Organs (less common but serious)
• Signs include anorexia, lethargy, weight loss, colic, pneumonia, fever, respiratory tract disease
• Require prolonged therapy and close monitoring with an overall worse prognosis
3️⃣ Lymphangitis/Vasculitis
• Swelling of the limbs (one or more can be affected)
• Inability/difficulty moving limbs
• Fever
• This form can mimic clinical signs of other conditions like cellulitis, purpura hemorrhagica, Strangles associated vasculitis, and lymphangitis
🩺 Diagnosis:
Your veterinarian can confirm the infection through:
• Bacterial culture
• SHI titer (blood test)
• PCR testing (purulent exudate, biopsy of affected tissue, internal abscess exudate)
💊 Treatment:
• Hydrotherapy
• Anti-inflammatories
• Abscess lavage and lancing
• Antimicrobials AT DIRECTION of your veterinarian
🛡️ Prevention Tips:
• Keep fly populations under control
• Isolate horses with draining abscesses
• Dispose of pus and bedding safely to reduce contamination
If you suspect your horse has Pigeon Fever, contact your veterinarian immediately.
Additional recourses:
AAEP Guidelines: https://aaep.org/resource/pigeon-fever-corynebacterium-pseudotuberculosis/
EDCC: https://www.equinediseasecc.org/pigeon-fever
