Haemorrhagic Septicaemia (HS)
Why in news?
Haemorrhagic Septicaemia (HS), a highly fatal bacterial disease caused by Pasteurella multocida, has led to multiple blackbuck deaths in Indian zoos in late 2025.
About
- Haemorrhagic Septicaemia (HS) is an acute, highly fatal bacterial disease primarily affecting cattle and water buffaloes in tropical regions like Asia and Africa.
- The disease thrives in humid, monsoon conditions with high morbidity and mortality rates up to 80-100% without early treatment.​
Causative Agent
- Pasteurella multocida serotypes B:2 (Asia, global) and E:2 (Africa).
- Gram-negative coccobacillus with capsules and toxins enhancing virulence.​
- Commensal in healthy animals but turns pathogenic under stress.​
Transmission
- Natural routes: ingestion or inhalation from infected carriers, contaminated water/feed, or fomites.​
- Spreads rapidly in overcrowded, stressed herds during monsoons.​
- Experimental via oral drenching, aerosols, or subcutaneous injection.​
Clinical Signs
- Phase 1: Sudden high fever (40-41°C), depression, anorexia.​
- Phase 2: Salivation, serous nasal discharge turning mucopurulent, submandibular/throat oedema spreading to brisket/forelegs, respiratory distress.​
- Peracute cases: Collapse and death in 6-24 hours; acute: 2-3 days.​
Pathology
- Subcutaneous oedema (straw-coloured or blood-tinged) in head, neck, brisket.​
- Petechial/ecchymotic haemorrhages in organs, serosal surfaces, lymph nodes.​
- Lung congestion, hydrothorax, gastroenteritis possible.​
Download Pdf
