Glanders is a contagious zoonotic disease caused by infection with the bacterium Pseudomonas mallei (formally classified as Burkholderia mallei). Glanders can occur as either acute or chronic, but clinically it is difficult to distinguish between the two forms. Donkeys and mules are more prone to developing the acute form of glanders, while horses often develop the chronic form. Chronic glanders is usually fatal albeit a few cases may recover clinically and remain carriers for life. Chronic glanders occurs as one of three forms: cutaneous (farcy), nasal, or pulmonary. The cutaneous form is characterized by development of nodules which progress to ulcers discharging a thick yellow exudate and generally track the lymphatic vessels to regional lymph nodes. The lymph vessels are usually swollen and corded with nodules. The cutaneous lesions can appear anywhere on the body, but typically affect the limbs, especially the hindlimbs.
Glanders has been eradicated from many countries by statutory testing, elimination of infected animals and import restrictions. However, it is still endemic in parts of Africa, Asia, the Middle East and Central and South America.
Glanders is transmitted primarily through ingestion of feed or water contaminated by the nasal secretions of infected horses.