|
Use this tool to help identify the pre-disposing conditions for the development of clostridial diseases and cheesy gland. If these conditions exist, adopt management strategies to prevent the diseases. Both clostridial disease and cheesy gland are prevented by vaccination.
|
Disease
|
Conditions when likely to occur
|
|
Clostridial Diseases:
|
|
|
Tetanus
|
- penetrating wound including marking wounds
|
|
Black leg
|
- muscle bruising, growing animals
|
|
Black disease
|
- liver fluke infestation
|
|
Malignant oedema
|
- wounds
|
|
Pulpy kidney
|
- lush pasture, heavy grain feeding, change of feed
|
|
|
With all clostridial disease consider the local risk based on previous local district history and property history
|
|
|
Intensification is likely to increase risk of clostridial diseases such as blackleg and pulpy kidney
|
|
Cheesy gland
|
Infection commonly through shearing cuts, but can penetrate skin of recently shorn sheep. Dipping sheep is a high-risk strategy. Infection is widespread, does not cause serious production losses on farm but is a major cause of economic loss to the meat industry due to condemnations and carcase trimming
|
|
Disease
|
Clinical signs
|
|
Clostridial diseases
|
- tetanus: stiff-legged gait followed by convulsions initially stimulated by sound or touch and gradually progress in severity
- black leg: severe lameness, swelling of affected leg, very depressed, fever, skin dry and cracked, often sudden death
- black disease: depression and abdominal pain, sudden death
- malignant oedema: contaminated wound, often associated with lambing, local swelling, fever, severe toxaemia and death
- pulpy kidney: convulsions, sudden death
With all clostridial diseases, veterinary assistance will be required to assist in
diagnosis with necropsy, bacteriology and histopathology
|
|
Cheesy gland
|
Abscesses develop in lymph nodes around the body
Abscesses are obvious in freshly shorn sheep
Sometimes sheep will cough if abscesses are present in the lungs
|
|
Vaccine
|
Strategy
|
|
Clostridial vaccine
|
For maximum protection of young lamb:
Vaccinate ewe 2–6 weeks before lambing
For protection of lambs:
Vaccinate at marking and give a booster 4–8 weeks later (weaning)
Older stock:
Annual booster timed before high-risk period or more frequently in high-risk situation, such as grain feeding in drought or grazing high-quality fodder crops
New stock
Implement vaccination procedures as for normal stock. If history of
vaccination known, implement flock program. If vaccination history not
known, give an initial dose, then booster 4–8 weeks later
Note that one dose does not provide any protection. In outbreaks of pulpy
kidney, removing stock from pasture will often stop deaths
|
|
Cheesy gland
|
Cheesy gland vaccine is incorporated in clostridial vaccine, either as 3-in-1 or 6-in-1. Initially two doses are required to provide protection, and then an annual booster is necessary to maintain it. Sucker lambs do not need vaccinating against cheesy gland as they are sold before abscesses develop. Dipping hygiene is important and sheep should only be dipped if attempting to eradicate lice. Sheep should be carefully shorn to avoid shearing cuts and not dipped until cuts have healed.
|
Vaccines available
Several companies sell vaccine as either 3-in-1 (pulpy kidney, tetanus, cheesy gland) or 5-in-1 (pulpy kidney, tetanus, black disease, blackleg, malignant oedema) or 6-in-1 (clostridial diseases and cheesy gland). Vaccines are also available in combination with vitamin B12 and trace elements such as selenium but should only be used when cobalt or selenium are deficient.
|
