Mortality among cattle and buffaloes in Sri Lanka due to haemorrhagic septicaemia.

Data on the mortality of cattle and buffaloes in 62 epizootics of haemorrhagic septicaemia (HS) in the HS enzootic and non-enzootic regions of Sri Lanka was collected and subjected to statistical analysis. It was found that the overall mortality for buffaloes was higher than for cattle (45.2 and 15.8% respectively, P less than 0.001). For buffaloes in enzootic areas only the overall mortality was 29% whilst in non-enzootic areas it was 64.5% (P less than 0.05). In the enzootic areas deaths were mainly confined to young animals whereas in the non-enzootic areas when sporadic outbreaks of HS occurred deaths were scattered over all age groups. The vaccines used, vaccination schedules adopted and the coverage of vaccination in these herds did not appear to influence the mortality among buffaloes in enzootic areas to a statistically significant degree.