Glanders

GLANDERS

Synonym: Farcy, malleus

Definition

  • It is a contagious disease of horses, mules and donkeys (solipeds), usually chronic in nature characterised by formation of nodules and ulcers of upper air passages, lungs and cutaneous tissue.

Aetiology

  • Pseudomonas mallei (Actinobacillus mallei )

Incidence

  • Horses, mules, donkeys, highly susceptible and man is moderately susceptible
  • Sheep and goats may be infected.
  • The disease is also transmissible to human beings

Transmission

  • Ingestion ,inhalation and through skin invasion

Pathogenesis

  • Infection is by ingestion and inhalation of organisms
  • Penetrating the pharyngeal and intestinal mucosa
  • Enters the general circulation and reach pulmonary capillaries
  • Septicaemic phase with high temperature
  • Forming emboli in the pulmonary capillaries
  • Acute inflammatory reaction in the perialveolar and peribronchiolar area
  • Serous exudate in the connective tissue
  • Penetrate the bronchial wall and enter lumen voided along with secretions
  • Aspirate into alveoli produce bronchopneumonia
  • Neutrophils undergo degeneration- karyorrhexis and fragments of nucleus seen as scattered manner - Characteristics of glanders in stained smears
  • Organisms enters circulation and localized in various organs produce nodules and ulcers in skin

Clinical signs

  • Acute: septicaemia with fever
  • Chronic : Two forms
    1. Pulmonary- Chronic cough, pneumonic signs, purulent oily discharge
    2. Cutaneous form- ulcers, oily pus discharge, coiled tortuous lymphatics

Gross lesions

Lungs

  • Miliary nodules
  • Pleurisy – fibrinous deposits
  • Ulcers in trachea and larynx (punched out)

Lymphatic glands

  • Swollen edematous with yellowish grey centers
  • Thick tortuous cords of lymph vessels (farcy cords)
  • Nodule formation in the lymph vessels (farcy buds)
  • Nodules may open and discharge oily pus with persistent ulcers

Microscopic lesions

  • The pulmonary lesions are granulomatous with caseous necrotic centre surrounded by epitheliod cells, giant cells and lymphocytes
  • Lymphangitis and lymphadenitis of the hind limbs in the form of thick tortuous cords of lymph vessels and nodule formation in lymph vessels.
  • The vessels are dilated and tightly packed with leucocytes.
  • Leucocytes infiltrate focally into the walls also giving them a beaded appearance. They nodules may open and discharge oily pus

Diagnosis

  • Lesions
  • Serological tests- CFT
  • Guinea pig inoculation (Straus test- male - suppurative orchitis within 4 to 5 days) and confirmation by intradermal mallein test
Last modified: Wednesday, 21 March 2012, 8:31 AM