Glanders in Horses: Nasal Ulcers, Lung Disease, and Zoonotic Risk
- See your vet immediately if your horse has thick yellow nasal discharge, nasal ulcers, swollen lymph nodes, coughing, weight loss, or draining skin nodules.
- Glanders is a serious bacterial disease caused by *Burkholderia mallei*. It is zoonotic, reportable, and often fatal in equids if infection becomes established.
- Horses may develop nasal, lung, or skin disease. Some infected horses can become chronic carriers with subtle signs, which increases spread risk.
- Diagnosis usually requires regulatory testing such as complement fixation, competitive ELISA, culture, and sometimes PCR, coordinated with animal health officials.
- There is no routine curative treatment approach for horses in disease-control programs. Management focuses on isolation, testing, quarantine, humane euthanasia of confirmed cases, and disinfection.
What Is Glanders in Horses?
Glanders is a contagious bacterial disease of horses and other equids caused by Burkholderia mallei. It can affect the nose, lungs, skin, and lymphatic system, and it is especially concerning because it can also infect people. In horses, the disease often follows a chronic course, while donkeys and mules may become sick more suddenly and severely.
This disease is considered life-threatening and reportable. In countries that are free of glanders, any suspected case is treated as a regulatory emergency. That means your vet may need to involve state and federal animal health officials right away, even before all test results are back.
Glanders is classically described in nasal, pulmonary, and cutaneous forms. Horses may have one form or a mix of several. Nasal disease can cause ulcers and sticky discharge, lung disease can cause cough and progressive weakness, and the skin form, often called farcy, causes nodules and draining tracts along lymph vessels.
For pet parents, the biggest takeaways are urgency and safety. This is not a wait-and-see problem. If glanders is on the list of possibilities, your horse needs prompt veterinary evaluation, strict isolation, and careful handling to reduce risk to other animals and people.
Symptoms of Glanders in Horses
- Thick yellow or mucopurulent nasal discharge, often persistent
- Nasal nodules or deep ulcers inside the nostrils or on the nasal septum
- Star-shaped scars in the nasal passages after ulcers heal
- Enlarged or firm submandibular lymph nodes under the jaw
- Coughing, exercise intolerance, or other respiratory signs
- Fever, especially in more acute infections
- Progressive weight loss, poor condition, and weakness
- Lung nodules, pneumonia, or chronic lower airway disease seen on testing
- Skin nodules along lymph vessels, especially on the legs or body
- Ulcerated skin tracts that drain sticky yellow pus
- Edema or thickened lymphatic vessels in cutaneous disease
- Septicemia and rapid decline in severe acute cases
Some horses show a slow, chronic pattern with weight loss, nasal discharge, cough, or recurring skin lesions. Others become much sicker, much faster. Donkeys and mules are more likely to have an acute, severe form, but horses can still become critically ill.
See your vet immediately if your horse has nasal ulcers, draining skin nodules, fever, trouble breathing, or unexplained weight loss, especially after importation, travel, contact with unfamiliar equids, or exposure to contaminated tack, feed, or water. Because glanders can infect people, avoid direct contact with discharge, wear gloves, and limit handling until your vet gives you a plan.
What Causes Glanders in Horses?
Glanders is caused by the bacterium Burkholderia mallei. Horses usually become infected by eating or drinking material contaminated with nasal discharge or pus from an infected animal. Spread can also happen through contaminated tack, grooming tools, harness equipment, feed buckets, water sources, and direct contact with skin lesions or mucous membranes.
The bacteria are present in nasal secretions and discharge from ulcerated skin lesions. Aerosol spread can occur, and the organism can enter through the respiratory tract, mucous membranes, or breaks in the skin. Humid, dirty conditions and crowding can make control harder, especially where biosecurity is limited.
A major challenge is that some horses can become chronic or latent carriers. These animals may have mild signs, low-grade fever, or no obvious signs at all while still posing a risk to other equids. That is one reason your vet may recommend testing exposed horses even if they look normal.
In the United States, glanders is considered a foreign animal disease, so suspicion often centers on imported animals, travel history, or contact with horses from regions where the disease still occurs sporadically. Your vet and animal health officials will use that history to guide testing and quarantine decisions.
How Is Glanders in Horses Diagnosed?
Diagnosis starts with a careful exam and history. Your vet will look for purulent nasal discharge, nasal ulcers, enlarged lymph nodes, lung disease, and cutaneous nodules or draining tracts. These findings can raise concern, but clinical signs alone are not enough to confirm glanders.
Definitive diagnosis usually involves regulatory laboratory testing. Common tools include the complement fixation test (CFT) for screening, competitive ELISA or Western blot for improved specificity in some situations, and culture of B. mallei from lesions when feasible. Real-time PCR may also be used for clinical case identification, although validation can vary by setting.
A mallein test has historically been used as a delayed-hypersensitivity test, but in many areas it has been largely replaced by serologic testing. Because false positives and false negatives can occur with some assays, your vet may recommend repeat or confirmatory testing and coordination with state or federal animal health authorities.
If glanders is suspected, expect immediate isolation, movement restrictions, and reporting while results are pending. That can feel overwhelming, but it is an important part of protecting your horse, nearby equids, barn staff, and your family.
Treatment Options for Glanders in Horses
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Urgent farm call or clinic exam
- Immediate isolation of the horse from other equids
- Basic PPE guidance for handlers
- Initial sample collection and reporting to animal health officials
- Short-term stall-side biosecurity and movement stop while awaiting next steps
Recommended Standard Treatment
- Veterinary exam and full exposure history review
- Regulatory reporting and case coordination
- Serologic testing such as complement fixation and confirmatory assays as directed
- Strict quarantine and barn biosecurity plan
- Humane euthanasia of confirmed cases where required
- Carcass handling, disposal planning, and premises disinfection guidance
Advanced / Critical Care
- Hospital-level supportive care for severe respiratory distress or septic illness while differential diagnoses are pursued
- Advanced imaging or endoscopy when your vet needs to rule out other causes of nasal or lung disease
- Expanded laboratory workup, repeated sampling, and intensive infection-control measures
- Large-premises outbreak management, exposed-horse testing, and extensive decontamination support
- Specialized occupational health coordination for exposed handlers
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Glanders in Horses
Bring these questions to your vet appointment to get the most out of your visit.
- What signs in my horse make glanders a real concern versus another cause of nasal discharge or skin nodules?
- Does this need to be reported to state or federal animal health officials today?
- Which tests are most appropriate first: complement fixation, ELISA, culture, PCR, or repeat testing?
- How should I isolate this horse right now, and what protective gear should handlers use?
- Which horses on the property are considered exposed, and do they need testing or movement restrictions?
- What cleaning and disinfection products are appropriate for stalls, buckets, tack, and trailers?
- What is the expected cost range for testing, quarantine, and premises management in my situation?
- If people may have been exposed to nasal discharge or wound drainage, what human medical steps should we take next?
How to Prevent Glanders in Horses
Prevention centers on biosecurity, import controls, and early detection. There is no vaccine for glanders, so the best protection is keeping infected animals and contaminated materials away from your horse. New arrivals should have a careful travel and health history, and imported equids should meet all testing and certification requirements.
Do not share water buckets, feed tubs, bits, tack, grooming tools, or transport equipment between unfamiliar horses without thorough cleaning and disinfection. If a horse develops suspicious nasal discharge, ulcers, cough, fever, or draining skin nodules, isolate that horse right away and call your vet before moving it.
If glanders is suspected or confirmed, your vet may recommend quarantine, testing of exposed equids, humane euthanasia of confirmed cases, safe carcass disposal, and rigorous disinfection of the environment. Organic debris should be removed before disinfecting. Agents reported as effective against B. mallei when used correctly include bleach solutions with 0.5-1% active chlorine, phenolic disinfectants, and quaternary ammonium compounds.
Because this disease is zoonotic, prevention also means protecting people. Wear gloves, eye protection, and a mask or respirator when handling suspicious discharge, lesions, or contaminated materials, and wash thoroughly afterward. If anyone may have been exposed, contact a human healthcare professional promptly.