Leptospirosis: Protect Your Herd & Family

Leptospirosis can affect people, livestock, and pets on your farm, with serious health consequences. Protecting your team and animals now helps keep your farm safe and productive.

The article below from Zoetis New Zealand outlines practical tips for controlling Lepto, including vaccination, pest management, and hygiene…

It’s never been a better time to check that you have control measures in place to protect your farm from Leptospirosis, an infectious disease that can cause severe disease in both people and animals. The human health effects of Lepto can be significant with symptoms ranging from a mild flu to life-threatening kidney and liver damage.

Lepto can cause severe disease in livestock, with possible symptoms including abortion, weak or stillborn calves, mastitis, drop in milk production, and sudden death in youngstock.  Pets can also become severely ill or die from Leptospirosis.

People can catch Lepto when they are exposed to leptospires (the infectious bacteria) passed from animals in urine. Leptospires thrive in wet conditions, especially when it’s warm and wet, and can be transferred to people via their eyes, nose, mouth, or skin wounds. There are different types of Lepto bacteria, known as serovars, which behave differently so it is important to understand the most common Lepto serovars to protect your farm.

The most common Lepto serovar in both humans and livestock in NZ is called Hardjo; apparently healthy cows can be infected with Hardjo, and their urine can be infectious to people for up to 2 years. Vaccination of livestock, use of personal protective equipment (e.g. wearing waterproof gear), and personal hygiene (e.g. covering cuts, washing hands) are simple but effective ways to protect people on your farm against Hardjo infection.

Recent research from Massey University has identified an increase in the number of human Lepto cases caused by the Ballum serovar since 2008, and Ballum is the second most common Lepto serovar in people. Ballum is carried by pest species such as rats, mice, and hedgehogs rather than livestock, so an effective pest control program is another crucial piece of the Lepto control puzzle. Remember that Lepto can survive well in wet environments, so protective equipment and personal hygiene are an important line of defence against Ballum.

These researchers have also identified another Lepto species, now named Pacifica, in NZ livestock. However, they have not found any cases of Pacifica causing disease in animals and there are no accurate figures to show how common this species is among people with Lepto. Pacifica is part of the Tarassovi “group” of Lepto bacteria; around 1 in 10 Lepto cases in people may be caused by Tarassovi “group” Lepto bacteria and these case numbers have not increased over the last 15 years.

Cattle, pigs, sheep, deer, goats, and dogs can all be vaccinated against Lepto. Success of your farm’s vaccination plan depends on using an effective vaccine, vaccinating animals before they get exposed to Lepto, and keeping up with booster vaccinations every year. Risk of Lepto infection is highest when the environment is wet, but changing weather patterns can make this hard to predict, so it is important to use a vaccine that will protect your animals in for a full year. Ultravac® 7 in 1 and Leptoshield® are both proven in clinical trials to protect for 12 months against Leptospirosis infection by the most important Lepto serovar, Hardjo.

To minimise the risk of Leptospira infection and subsequent shedding, calves should be vaccinated early, before they are exposed to the organism.

Under Zoetis vaccination protocols, calves should receive an initial two-dose primary course, with the first vaccination typically given from 4–6 weeks of age, followed by a second dose 4–6 weeks later (depending on product label directions). Protective immunity is not fully established until after completion of this primary course, so early timing is critical.

Vaccinating calves at this stage helps:

• Reduce the risk of clinical disease
• Prevent establishment of renal infection
• Reduce or prevent urinary shedding, which is a key source of human exposure

Once calves have completed their primary course, they should then be integrated into the farm’s whole-herd annual booster programme.

How does this differ from herd booster vaccination?

• Calf vaccination focuses on building initial immunity before first exposure, particularly during high-risk wet periods or when calves are first mixed, grazed off-farm, or introduced to contaminated environments.
• Herd booster vaccination involves annual revaccination of all adult stock to maintain immunity and reduce long-term shedding, particularly for Hardjo, which can persist in apparently healthy cattle for up to two years.

For optimal protection of both people and livestock, calf priming and annual herd boosters must work together as part of a whole-farm Leptospirosis control programme, alongside pest management and good hygiene practices.

Always consult your veterinarian to tailor vaccination timing to your farm system, risk profile, and product label requirements.

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References

Zoetis New Zealand Limited. Tel: 0800 963 847; www.zoetis.co.nz. Ultravac & Leptoshield are registered trade marks of Zoetis. ACVM Nos. A6935, A3734, A7426.ESR Notifiable Diseases in New Zealand Annual Reports 2010-2022

Nisa, S., et al., Diverse Epidemiology of Leptospira serovars Notified in New Zealand, 1999-2017. Pathogens, 2020. 9(10).

Wilkinson, D.A., et al., Identification of pathogenic Leptospira species and serovars in New Zealand using metabarcoding. PLoS One, 2021. 16(9): p. e0257971.

Yupiana, Y., et al., Emerging Leptospira strain poses public health risk for dairy farmers in New Zealand. Prev Vet Med, 2019. 170: p. 104727.