Glanders is one of the oldest known diseases of the horse. It has now been eradicated in the United Kingdom and much of the world, although it is still reported in the Middle East, Pakistan, India, China, Brazil and Africa. The disease is caused by a bacterium called Burkholderia mallei and is a zoonosis, that is, infectious to people, with a 95% fatality rate, if untreated.
The disease is characterised by nodules or ulcers on the skin and in the respiratory tract, but is more often seen in a chronic or latent form. These chronically infected horses act as a reservoir of disease. Glanders is contracted by ingestion of food or water contaminated with nasal discharges of carrier animals or by ingestion of contaminated meat from infected horses. After an incubation period of 3 days to 2 weeks animals can develop acute or subacute respiratory symptoms or cutaneous symptoms.
Acute respiratory glanders is mainly seen in asses and mules,who are most severely affected. Symptoms include high fever, cough, nasal discharge and ulcers on the nasal mucosa. As the disease progresses respiratory signs develop and the animals often die.
The chronic disease is more often seen in horses and is commonly seen with both the cutaneous and respiratory forms, symptoms are slower to develop. In the respiratory form symptoms include; ulcers in the nasal passages, with nasal discharge, chronic pneumonia and scaring of the submandibular lymph nodes. In the cutaneous form (‘farcy’) nodules appear to course along the lymph nodes and degenerate to form ulcers that discharge a highly contagious sticky pus. The liver and spleen may also develop similar nodules.
Clinical signs develop when the disease is well advanced so diagnosis is best made by the use of diagnostic such as CFT antibody test or PCR test of infected skin tissue. Treatment of Glanders with antibiotics can be attempted in endemic countries, but often results in latent disease. In counties where Glanders has been eradicated, animals with confirmed disease are euthanased and in contact animals are tested to monitor disease status.