ANTHRAX

  • Also known as spleenic fever, miltzbrand, charbon, wool sorter's disease and Tarka.
  • It is an acute widespread infectious disease of livestock which occurs throughout the world.
  • It is characterised by septicemia, exudation of tarry coloured blood from natural orifices due to absence of blood clot, sudden death and absence of rigor mortis.

Etiology

  • It is caused by a spore forming aerobic capsulated G +ve bacteria i.e Bacillus anthracis

Mode of transmission

  • Transmission occurs through ingestion, inhalation and through skin
  • Ingestion of contaminated feed and water may lead to entry of spores and injuries of mucous membrane in digestive tract facilitate infection.
  • Spores can be picked up directly from the soil. Fodder grown on infected soil act as a source of infection.

Clinical findings

Disease appear in per acute and acute form-

  • Per acute form-
    • Most common form
    • Last for about 1-2 hours
    • Animal may found dead without any clinical signs
    • Signs like fever, muscle tremor, dyspnoea, and congestion of the mucosa are seen.
    • Animal may collapse and usually seen dead after terminal convulsion.
    • After death blood oozes out from natural orifices.
  • Acute form-
    • Course is about 48 hours.
    • Body temperature increases and reaches around 107F along with onset of sudden depression.
    • Short period of excitement is noticed initially.
    • Respiration becomes rapid and deep.
    • Mucosa appears congested and haemorrhagic.
    • Heart rate increases
    • Signs like complete anorexia, ruminal stasis, reduction in milk yield and diarrhoea are noticed.
    • Milk becomes blood stained or deep yellow in colour.
    • Edema of tongue is seen.

Diagnosis

  • From clinical signs and symptoms
  • From microscopic examination of blood films using polychrome methylene blue or Giemsa's stain (McFadyean's reaction), large square ended blue rods are seen is short chain with pink capsule.
  • Cultural examination using nutrient broth and 5% blood agar.
  • Animal inoculation test
  • Serological test- Ascoli's thermoprecipitation test
  • Fluorescent staining
  • Sero diagnosis- ELISA

Differential diagnosis

  • Lightening stroke
  • Electric injury
  • Acute tympany
  • Black quarter
  • Snake bite
  • Prussic acid poisoning

 

Treatment

  • Antibiotics and anti-anthrax serum should be administered.
  • Penicillin- 10000 IU per kg bwt BID
  • Antisera 100- 200 ml daily i/v for 5 days

Control

  • Feed materials should be checked properly before feeding
  • Fodder from contaminated pasture should be destroyed.
  • Strict quarantine and isolations protocols should be followed in case of outbreak.
  • Carcass should not be opened and should be buried using deep burial system with quick lime.
  • Area should be disinfected with 3% acetic acid, 10% caustic soda and 10% formalin
  • Hides, wools and bone meals should be sterilised with gamma irradiation.

Immunisation

  • Animals should be vaccinated annually prior to anthrax season.
  • Sterne vaccine
  • Avirulent spore vaccine
  • No risk of causing anthrax following vaccination

Produce strong immunity