Clostridial diseases kill cattle fast. Blackleg can drop a thriving yearling steer within 24 hours of the first symptoms; pulpy kidney can kill a well-grown calf between one inspection and the next with no warning at all. These diseases are caused by Clostridium bacteria that are ubiquitous in Australian soils — present on virtually every property in the country, waiting for the right conditions to cause disease in unprotected animals. The good news is that prevention is straightforward, cheap, and highly effective. Annual vaccination with the right product is the non-negotiable foundation of any Australian cattle health program.

What does 5-in-1 cattle vaccine cover?

A 5-in-1 clostridial vaccine protects against five bacterial diseases caused by Clostridium species:

  • Blackleg (Clostridium chauvoei) — causes sudden death from gas gangrene of the muscles, most commonly in fast-growing young cattle on lush pasture or following injury. The affected muscle has a dark, gas-filled, rancid appearance. Mortality is almost 100% in unvaccinated animals once clinical signs appear.
  • Malignant oedema (Clostridium septicum and others) — wound-entry infection causing rapidly spreading swelling and tissue death, typically following injury, difficult calving, or castration. Often associated with blackleg vaccines as the organisms are related.
  • Pulpy kidney / enterotoxaemia (Clostridium perfringens type D) — the most common clostridial disease in cattle on high-energy diets or lush pasture. Toxins produced in the intestine cause sudden death, often in the best-conditioned animals in the mob.
  • Black disease (Clostridium novyi type B) — liver fluke damage provides the anaerobic environment for bacterial growth, leading to sudden death. Most relevant in fluke-endemic areas of eastern and southeastern Australia.
  • Tetanus (Clostridium tetani) — enters through wounds (including marking wounds — castration, dehorning, ear tagging), causes progressive muscle spasm and lock-jaw. Almost invariably fatal if untreated; preventable by vaccination.

The major registered 5-in-1 products in Australia include Ultravac 5-in-1 (Zoetis) and Glanvac (Elanco). These products differ slightly in their adjuvant formulation and shelf life — read the product insert and store appropriately (2 to 8°C, never freeze).

What does 7-in-1 cattle vaccine add?

A 7-in-1 vaccine provides the same five clostridial disease coverage as the 5-in-1, plus protection against two serovars of Leptospira:

  • Leptospira hardjo — the most common leptospirosis serovar in Australian cattle. Causes reproductive losses (abortion, stillbirth, reduced conception rates), milk drop in dairy cows, and occasionally acute illness. Critically, it is a zoonosis — humans contract it from infected cattle urine through skin abrasions or mucous membrane contact.
  • Leptospira pomona — causes more severe acute disease in cattle and is a significant zoonotic risk in areas with high wildlife populations (pigs, rodents) that serve as reservoir hosts.

The major 7-in-1 products registered in Australia include Ultravac 7-in-1 (Zoetis) and Leptavoid-H (MSD Animal Health). Not all 7-in-1 products cover the same leptospira serovars — check the registered coverage for the specific product you use.

Should you use 5-in-1 or 7-in-1?

The decision comes down to leptospirosis risk on your property and the human exposure risk in your operation. Use 7-in-1 if any of the following apply:

  • People work closely with cattle — particularly if children, pregnant women, or immunocompromised individuals are regularly in contact with cattle, their urine, or contaminated water sources
  • Your property has standing water, irrigation channels, or areas used by wildlife (pigs, rodents, deer) that serve as leptospirosis reservoir hosts
  • You are in a region with known leptospirosis in cattle (consult your vet — leptospirosis prevalence varies significantly by region)
  • You have reproductive problems (abortion storms, reduced conception rates, unexplained milk drop in any dairy animals) that may be leptospirosis-related
  • You purchase cattle from unknown health backgrounds — leptospirosis exposure history is rarely documented in commercial cattle sales

The cost difference between 5-in-1 and 7-in-1 is small (typically $0.50 to $1.50 per head per year). If you are on the fence, the 7-in-1 is a reasonable default for most Australian beef operations, and is strongly recommended for any operation where people handle cattle regularly.

The sensitisation protocol for naive cattle

A single injection of a clostridial vaccine in a previously unvaccinated animal does not provide full protective immunity. Two injections 4 to 6 weeks apart are required to prime the immune system for a full protective response — this two-dose sensitisation is mandatory for any animal with no documented vaccination history. Failure to complete the sensitisation leaves animals with only partial protection that may not withstand a genuine disease challenge.

The sensitisation schedule for different classes of cattle:

  • Calves: First dose at marking (4 to 8 weeks of age), second dose at weaning (approximately 6 months). Both doses of the same product.
  • Purchased adult cattle with unknown vaccination history: Treat as naive — give two doses 4 to 6 weeks apart immediately after purchase, before they mix with your existing herd.
  • Purchased adult cattle with documented annual vaccination: A single annual booster maintains protection — no resensitisation needed if the last annual booster was within 12 months.

After the initial two-dose sensitisation, a single annual booster maintains immunity. There is no evidence that boosting more frequently than annually provides additional protection for clostridial vaccines in adult cattle.

Annual booster timing: when to vaccinate

Timing the annual booster to maximise protection at the highest-risk period is more important than many producers realise. The key principle is: vaccinate 4 to 6 weeks before the highest-risk period, so that peak antibody levels coincide with peak disease risk.

For southern Australia with spring calving systems, give the annual booster in late winter (July to August) — 4 to 6 weeks before calving begins in September. This timing serves two purposes: it protects the cow through the calving period (the highest-risk time for tetanus via obstetric injury) and it boosts colostral antibody concentrations that protect newborn calves through their first weeks of life before they can be vaccinated directly.

For northern Australia with wet-season calving, time the booster for the dry season (April to May), again 4 to 6 weeks before calving begins with the wet season. Pulpy kidney risk is highest when cattle move from dry-season poor pasture to high-energy wet-season flush — having peak vaccine protection at this transition is critical.

For newly sensitised purchased cattle: complete the two-dose sensitisation as soon as possible after purchase, regardless of the calendar timing for the rest of the herd. Do not wait for the annual booster round — a naive animal that dies of blackleg in the first month on your property represents the cost of vaccination many times over.

Handling and storage

Clostridial vaccines are biological products that are destroyed by incorrect storage. The entire cold chain from manufacturer to needle must be maintained — this means:

  • Store in a refrigerator at 2 to 8°C at all times. Never freeze, and never allow the vaccine to reach temperatures above 25°C for any significant period.
  • Use an insulated vaccine cooler with ice bricks during field work. On hot summer days, a vaccine left in a vehicle for 30 minutes may be compromised.
  • Use the vaccine within the time specified on the label after opening the bottle — multidose vials have short use-by periods once punctured.
  • Use a clean needle for each animal where practical, and always use a new needle if a needle becomes visibly contaminated with soil or faeces.
  • Record the batch number, expiry date, and number of doses administered from each vial. This is good practice and may be required for NVD (National Vendor Declaration) compliance.

Withholding periods and ESI

All registered cattle vaccines have a withholding period (WHP) for meat and, for dairy products, a milk WHP. Check the current product label for the registered WHP — these are product-specific and can change if the registration is amended. The Export Slaughter Interval (ESI) is also product-specific and must be observed for cattle destined for export markets. Do not slaughter cattle within the WHP or ESI of any administered product — record administration dates to ensure compliance.

What clostridial vaccines do not cover

A 5-in-1 or 7-in-1 clostridial/leptospirosis vaccine does not protect against bovine respiratory disease (BRD), bovine viral diarrhoea (BVD), infectious bovine rhinotracheitis (IBR), pinkeye, or tick fever. Properties with specific disease pressure for these conditions should discuss additional vaccination options with their vet — IBR and BVD vaccines are the most commonly added to the program in feedlot or high-turnover operations with significant purchased cattle exposure.

For more on Australian cattle health management, see our Cattle Health Guide and Cattle Breeds Guide.

For more, see our Cattle Health in Australia: Vaccination, Drenching and Key Diseases and Beef Cattle Breeds in Australia: Choosing the Right Breed for Your Property.