They can live for a few hours and pass to other animals who eat or drink. The vet knows the disease may be HS if many cows die with swellings in the throat. It should consist of intravenous injections of broad-spectrum antibiotics or sulphonamides. Recovery is possible when treatment is undertaken early. For animals treated too late, or not treated at all, the mortality rate is high.
Vaccines are available that give immunity lasting for a year.
Immunity starts about 2 weeks after vaccination. Calves should be more than 3 months before vaccination is given, but before this age they may acquire some immunity by suckling the milk of vaccinated dams. Your animals may recover if you treat them early .