2. There are 5 common sheep diseases caused by Clostridia bacteria: pulpy kidney, black disease, malignant oedema, blackleg and tetanus.

3. The major signs of Clostridial disease are what producers might recognise. Black disease and pulpy kidney affect internal organs and progress rapidly so they might only see depression then rapid death but also convulsions if it is pulpy kidney. Malignant oedema and blackleg are sudden, severe infections on skin and muscle. They might only see the advanced infection with swelling containing fluid or the skin or muscle may be rancid and discoloured black. The sheep are depressed and die rapidly. With tetanus sheep have a stiff gait, general muscle spasms and an overreaction to noise or touch as you approach. This leads to convulsions and death.
Autopsy can find pulpy kidney and black disease – though some training is needed on what producers are looking for.
The impact of Clostridial disease can vary because: any class of sheep can be infected; numbers affected can be a few or many; it is very rare for sheep to survive; and treatment mostly fails because it is not seen early enough.

4. Clostridium bacteria are everywhere in the sheep or environment so the potential for disease is high. But some type of trigger in the sheep or environment is needed to cause each different disease. Unfortunately, the triggers occur commonly so the likelihood of disease is high.
Triggers include liver fluke, change in diet (with suckling, growing seasons or supplementary feed) and any wound or bruising (accidental with ram fighting, lambing, lactating or normal husbandry of shearing, marking, dipping, yarding).
The conclusion producers should come to on assessing their risk is: The continuous presence of Clostridia bacteria, the commonly occurring triggers and the variable impact makes the risk of disease high which is why preventative vaccination is common.

5. The important management intervention is between the sheep and Clostridium bacteria through vaccination.

6. Clostridial vaccines can include cheesy gland as part of a routine vaccination program. Whether producers choose just pulpy kidney and tetanus depends on the enterprise risk of black disease, blackleg and malignant oedema so producers should seek advice on their risk of these last 3 diseases.
Wether cheesy gland is chosen or not depends on the age producers market their sucker lambs, if young enough and not exposed to shearing or dipping or other skin wounds they might not have developed abscesses by kill time. Routine vaccination may also include Ovine Johne’s Disease, scabby mouth and anthrax where protection is warranted.
Making More from Sheep: Prevention of Clostridial diseases and cheesy gland
University of
Vaccination programs for sheep Agfact A
How vaccination works Agnote DAI/190
Clostridial diseases (includes all livestock)
Livestock vaccination
Clostridial diseases of livestock (includes all livestock)
Lamb vaccination
Sheep Diseases – The Farmers’ Guide
- click on link on this page
Cheesy gland or CLA
Pulpy kidney (enterotoxaemia) of sheep

7. The advice on the vaccine packet should be followed for complete immunity as each brand may have slight variations in the timing of booster shots, but the key principles for Clostridia and cheesy gland are outlined in the following slide.
Assume that sheep without any history of vaccination haven’t been vaccinated.
Remember that not every vaccination will be 100% effective because every sheep’s immune system is different.

8. The key principles for immunity are any unvaccinated sheep at any age needs a priming shot and a booster in a month (depending on the vaccine product). Ewes that have been correctly vaccinated before lambing will transfer immunity to their lambs via their milk to protect lambs up to about 8 weeks old. Thereafter lambs need their priming shot. Annual boosters are needed to continue that immunity. Cheesy gland needs lifelong annual boosters whereas life protection for pulpy kidney is gained by 2 boosters a year apart and tetanus just one booster.
Producers’ management may not achieve prevention because they don’t achieve 100% immunity. They might not have the opportunity to give a booster shot in combination with another sheep handling or yarding practice. This commonly occurs with weaners missing their booster shot or ewes not done before lambing. However adult sheep (including fleece shedding sheep) could be done at an annual events such as shearing, crutching, classing, worming or pregnancy scanning if the timing is right. Rams and wethers should not be ignored as we have seen that the bacteria are everywhere and all sheep are exposed to at least one of the triggers.
Sydney VEIN: Sheep health and production Chapter 14 Sudden Death
Coopers Effective vaccination programs for sheep, cattle and goats

9. Customised vaccination schedules may be valid
Customised vaccination schedules may be valid. For example, it may be okay to not give the follow up shot to weaners 4 weeks after the priming shot at lamb marking if the enterprise risk period for pulpy kidney is only in lambs younger than 14 weeks. Producers may not give pregnant ewes a booster for pulpy kidney before lambing if there is no risk to lambs before their priming vaccination at lamb marking. Producers may shift the timing of an annual booster to 2 weeks before a change in diet or in early summer before fluke season and not stick to a 12 month interval or they may not give any annual boosters if the risk is only as hoggets. However, these decisions are best made with professional advice to lower risk of an outbreak.

10. Besides routine vaccination, some of the risk from disease triggers can be reduced by stopping liver damage from fluke, treating wounds early with antibiotics (especially keep an eye on rams), making sure lamb marking, dipping, shearing, crutching is as hygienic as possible and removing the opportunity for injury from sheep handling facilities.

11. Treatment of existing cases of Clostridial diseases is mostly unsuccessful and efforts should be concentrated on the mob and flock. Pulpy kidney outbreaks respond to a check in the quality or quantity of the diet because it reduces the number of bacteria producing the toxin. Lamb marking or weaning reduce intake and offering roughage or moving to poor paddocks reduce the feed quality. If the mob or flock is unvaccinated then vaccinate it.

12. There may be some success with some individual sheep early in the disease whose value justifies individual treatment e.g. rams with tetanus, malignant oedema or blackleg otherwise vaccinate the unvaccinated.

15. Question 1: Before knowledge test
How long is the likely protection from a 5 in 1 vaccine for pulpy kidney given to a lamb at lamb marking?
a) 1 month (correct answer)
b) 2 months
c) 6 months
d) 12 months
e) Unsure

16. Question 2: After knowledge test
Which of the following statements is false about Clostridial diseases?
a) Lambs are protected up to 8 weeks old by the milk of their correctly vaccinated dams
b) A maiden ewe needs to have been vaccinated only once for her to be able to protect her first lamb (correct answer)
c) Rams need vaccinating with 5 in 1 because they are prone to fight wounds
d) 5 in 1 vaccine is needed in fluke country
e) Unsure

17. Question 3:
How confident are you to implement an effective Clostridial vaccination program? (choose the number corresponding to your level of confidence)