farcy

Farcy is the external cutaneous form of glanders, a contagious infectious disease of horses, donkeys, and mules caused by the bacterium Burkholderia mallei. In farcy, the infection progresses along superficial lymphatic channels, producing nodular swellings known as farcy buds that may ulcerate and discharge. Affected animals often have swelling of the limbs, fever, and malaise; nasal involvement is more typical of the nasal form of glanders but can occur in cases with mixed presentations.

Pathogenesis and transmission: Burkholderia mallei is an intracellular pathogen. The disease spreads through contact with infected exudates or nasal secretions and can be transmitted via contaminated equipment. The organism survives poorly in the environment, making direct animal-to-animal contact the primary route of transmission in most settings.

Diagnosis: Suspected on clinical signs and history, followed by laboratory confirmation. Diagnosis relies on culture of material from lesions, supported by serological tests and molecular methods. Historically, the mallein test has been used to aid detection, but modern approaches include ELISA and PCR. Because glanders and farcy are notifiable diseases in many jurisdictions, timely reporting is important for public and animal health.

Treatment and control: There is no reliably curative therapy for glanders in horses; treatment is generally ineffective due to intracellular persistence. Control measures emphasize surveillance, quarantine, movement restrictions, and humane depopulation of confirmed cases. Vaccines have not provided a controlled solution, and eradication programs have reduced incidence in many regions.

Zoonotic risk and status: Burkholderia mallei can infect humans, typically causing severe disease such as pneumonia or cutaneous lesions; human cases are rare but can be serious. The disease remains notifiable in many countries, with eradication and strict biosecurity as central components of control efforts.