Black leg (clostridial disease)
Conditions when likely to occur:
Muscle bruising, growing animals
Clinical signs:
Severe lameness, swelling on affected leg, very depressed, fever, dry and cracked skin, often sudden death.
Management strategy to prevent disease:
Clostridial vaccines prevent mortality against black leg, black disease, tetanus, pulpy kidney and malignant oedema.
For maximum protection of young calves:
- Vaccinate cow 2–6 weeks before calving.
For protection of calves from unvaccinated cows:
- Vaccinate early and a booster 4–8 weeks later.
For protection of calves from vaccinated cows:
- Vaccinate calves at 6–8 months and booster 4–8 weeks later.
Older stock:
- Annual booster timed before high-risk period or more frequently in high-risk situation, such as grain feeding in drought.
New stock:
Implement vaccination procedures as for normal stock. If history of vaccination known, implement herd program. If vaccination history not known, give a sensitising dose then booster 4-8 weeks later.
More information on clostridial diseases including causes, prevention and treatment can be found on the primefacts factsheet provided by the NSW Department of Primary Industries.