Vet’s Vision Phil Rennie Tauranga Vets

Leptospirosis remains a serious threat to the health and livelihood of farmers. While control of lepto in New Zealand dairy cattle has improved markedly thanks to widespread vaccination, evidence remains that there is still room for improvement.

Every year almost 100 cases of leptospirosis are reported in humans, and it is estimated the numbers of unreported or undiagnosed cases are even higher. Farmers or farm workers have a four to seven per cent chance of contracting leptospirosis, which is a risk 25 to 50 times higher than the average person in NZ.

Traditional vaccination programmes in calves have delayed vaccination until about six months of age. This has been due to a belief that calves are not at great risk of infection before six months and also because of doubts about how effective the original lepto vaccines were when given to very young calves.

We now know calves are at risk of lepto infection well before six months of age. And if they do become infected they can become chronic shedders of leptospirosis in their urine for months or years, presenting a health risk to you any time they are handled. Once infected, vaccination is too late to be of any use and will not cure their infection.

Therefore, calves need to be vaccinated early before they have a chance to become infected. Fortunately, there are vaccines that are effective in young calves, such as Ultravac7 in 1, which can both be used as early as four weeks of age. Early calf vaccination with two injections four to six weeks apart, then yearly boosters, is the best way to protect you, your family and your valuable employees from this debilitating disease.

The figure below is a summary of the original NZ research showing vaccinating earlier than six months of age subsequently reduces the risk of urine shedding in a herd.

A convenient time to do early calf lepto vaccinations is at the same time as 5 in 1 clostridial vaccination. This is possible with Ultravac 7 in 1, a vaccine that provides protection against leptospirosis and clostridial disease in one simple shot.

Therefore, in keeping with current risk management best practice, leptospirosis early vaccination course for calves from two to three months of age in the spring followed by a third shot in the autumn is recommended.

For further information about early calf lepto vaccination and lepto control, speak with your local vet clinic today.