In New Zealand Leptospirosis is a significant zoonotic disease risk (humans can contract it from animals) and as such its management is a very important aspect of health and safety when working with livestock.
Leptospirosis a contagious bacteria that localises in the kidneys and is spread in the urine of a variety of animals including rats, pigs, sheep, cattle and deer. It survives in wet environments, particularly pools of stagnant water, which can harbour leptospirosis organisms for long periods of time. Consequently the likelihood of infection increases during periods of high rainfall or flooding.
In cattle the signs of infection can include lethargy, abortion, fever, haemolytic anaemia (red urine), jaundice, mastitis, diarrhoea and anorexia. Death can be the outcome, especially in calves which are highly susceptible to infection. Once an animal becomes infected with leptospirosis, it is capable of shedding large numbers of bacteria into the environment.
Vaccination of animals is the best means of controlling infection and is especially important in preventing human disease. Humans contract leptospirosis most commonly through urine splashes to the face but also with contact of urine to any abrasions or cuts. Symptoms initially resemble the flu however, if untreated, can develop into severe nausea, vomiting, headaches and in some cases liver and kidney failure.
The most common vaccination protocol is giving two injections four to six weeks apart, followed up by yearly boosters. Cattle that are vaccinated in the last four to six weeks of pregnancy transmit some protection to their calves through the colostrum. However it is recommended that calves are vaccinated as soon as possible to provide the best protection, generally at around four to eight weeks old as it can be done at the same time as disbudding. Annual boosters are required in all age groups, and often this is administered prior to the autumn rainfall which is the greatest risk period for contracting leptospirosis.
Other means of preventing Leptospirosis includes fencing of waterways, minimising presence of rodents, good hygiene practices (including NOT eating or smoking in the dairy shed) and avoiding contact between cattle and pigs/deer.
If you would like to know more please don't hesitate to make contact and discuss it with your vet.