printStock Journal Article: April 2026
Author: Colin Trengove, Pro Ag Consulting
One of the most common and preventable causes of death in sheep is pulpy kidney disease or enterotoxaemia, caused by Clostridium perfringens. This disease originates in the intestine and can kill rapidly, often affecting the best-growing animals in the mob.
The good news is that it is easily prevented.
The 6-in-1 vaccine protects against pulpy kidney/enterotoxaemia as well as tetanus, malignant oedema, blackleg, black disease and cheesy gland. It is one of the most cost-effective animal health tools available. Preventing losses of as little as 1% of stock each year will generally cover the full cost of a vaccination program. In most flocks, the return on investment is far greater than that.
Timing is critical
For long-lasting protection, ewes should be vaccinated about one month before lambing. This allows protective antibodies to pass into the colostrum and milk, giving lambs passive immunity for up to 12 weeks.
Lambs then require:
- A priming dose of 6-in-1 at marking
- A booster 4–6 weeks later, usually at weaning
A single priming dose provides only short-term protection — around three months. The booster is essential to stimulate a stronger, longer-lasting immune response, extending protection for up to 12 months. Skipping the booster is one of the most common causes of vaccine failure.
Annual boosters are then required to maintain immunity in adult sheep.
Vaccine handling makes the difference
Vaccination is only effective if the product is handled correctly.
Vaccines must be stored at refrigerator temperature until use and kept cool while working in the yards. Heat, sunlight and contamination reduce effectiveness.
A multi-dose vaccine gun attached directly to the vaccine pack helps minimise contamination. After use, thoroughly clean and sterilise the gun by boiling and flushing with boiling water. Re-using opened vaccine packs or failing to sterilise equipment increases the risk of infection and abscess formation.
Injection technique matters
Vaccines must be administered under the skin, not into muscle.
Use a ¼-inch, 18-gauge needle. Longer needles can penetrate muscle and increase the risk of abscesses. Inject high on the neck, below the ear, at a 45-degree angle to avoid damaging high-value meat cuts.
Change needles frequently. Blunt or burred needles tear skin, increase pain and predispose sheep to abscesses. Using one hand only when injecting reduces the risk of accidental self-injection.
Attention to these small details significantly improves animal welfare and carcass quality outcomes.
Why programs fail
When vaccination programs don’t deliver results, the cause is usually management rather than the vaccine itself. Common mistakes include:
- Vaccine not kept refrigerated
- Dirty or blunt needles
- Failure to sterilise equipment
- Re-using opened packs
- Using needles longer than recommended
- Incorrect injection placement
- Giving a priming dose without a booster
- Using product past its expiry date
Most vaccines are killed (inactivated) products. They require two initial doses to establish immunity, followed by annual boosters to maintain protection. Some live vaccines, such as Scabigard, stimulate longer-lasting immunity but still require correct administration and handling.
A simple risk management tool
Vaccination is one of the simplest and most reliable risk-management tools available to sheep producers. In an industry where margins are often tight, losing even a small percentage of stock to preventable disease is unnecessary and costly.
A well-managed vaccination program protects productivity, improves animal welfare and safeguards profitability.
Prevention is always cheaper than losses.