Lepto 4 Way
March 2024

With Autumn approaching, herd Leptosporosis vaccinations are just around the corner. Leptosporosis (lepto) infection is spread by contact with urine of an infected animal, either directly or indirectly (eg. from contaminated water). In young calves, lepto can cause fever, “red water” (discoloured urine), and loss of appetite. Less commonly, adult cattle can be affected causing reproductive losses, sudden decreases in milk production, and jaundice. Human infection with lepto can be severe, causing flu-like symptoms and in some cases hospitalisation.

Traditionally herds have been vaccinated with Lepto 3-Way, however, Lepto 4-Way has recently come onto the market. Lepto 4-Way offers protection for all three strains present in the 3-Way vaccine (Hardjo, Copenhageni and Pomona) as well as the strain Pacifica.

Lepto Pacifica has been labelled as New Zealand’s emerging lepto strain, with recent research suggesting that Pacifica could be present in almost 75% of dairy herds. Cases of lepto in dairy farm workers on vaccinated farms have spiked in the last few years, suggesting many of these infections may be from this new strain, and often with more severe symptoms seen. Cattle seem to be the “maintenance” host for this type of lepto, so do not show signs of disease.

Vaccinating cattle with Lepto 4-Way provides an immune response against the Pacifica strain, reducing shedding in the urine, helping to protect farmers, workers, and other people on farm from being infected.

Because the Pacifica strain has not been available in vaccines before and the vaccination does not contain live bacteria, a booster in 4-6 weeks after initial vaccination is required. This stimulates the body’s “memory” to provide immunity until the following annual booster. In calves, it is important that the vaccination programme is started early to limit the risk of animals becoming carriers of lepto prior to vaccination.

While vaccination for lepto is important to limit the spread of disease, other factors for protection need to be considered as well. Staff training is important to make sure everyone is aware of lepto and the risks; avoid contact with urine by wearing appropriate PPE and implement good personal hygiene. Lepto can survive in wet conditions for up to six months, so effluent and waterway systems need to be well managed. As rodents can be hosts for some strains, bait stations should be well maintained, and food sources need to be rodent proof. New stock on farm should be vaccinated prior to entry, and if there are sheep, deer or pigs on farm they should also be vaccinated.

Vetora will start using Lepto 4-Way this year, with 2024 born calves being vaccinated and boosted with the 4-Way, and herd immunity developing over successive years. If you’d like to jump straight in to vaccinating your herd with Lepto 4-Way, we can organise a booster shot for the herd four to six weeks later.