Leptospirosis can have a significant impact on dairy herd causing economic losses through increased abortions and calf deaths.
It is a serious infectious disease caused by bacteria, which can affect a range of animals including cattle and humans.
An integrated approach to prevent leptospirosis should consider:
vaccinating the whole herd (following directions on the vaccine label);
developing and implementing a farm biosecurity plan; and
considering the risk of introducing infection when bringing in stock and only purchasing animals with an animal health statement.
Agriculture Victoria and Dairy Australia have worked together to develop a biosecurity tool to assist dairy farmers create a farm biosecurity plan tailored to their farm.
Farmers can access the tool using this link (Biosecurity Plan Tool) to manage their farm and herd’s risks to 14 separate diseases.
If a farmer suspect leptospirosis, confirmation requires testing from their veterinarian.
The occurrence of a severe outbreak in a herd is often due to the introduction of an infected animal to an unexposed and unvaccinated herd.
Spread can be through exposure to contaminated water, food, pastures and soil or contact with tissue or urine of infected animals.
The severity of the disease is highly dependent on the host and strain.
Symptoms of the disease depend on the infecting strain, which means cases may pass unnoticed.
Some of the signs that could lead to a suspicion of leptospirosis in a herd include:
-abortion or still births;
-decline in quality and quantity of milk;
-bloody, port wine coloured urine;
-rough, dry coat; and
-severe fever and death in young animals.
Leptospirosis is recognised as a serious occupational health hazard for humans.
The dairy is a key contact point, due to urine splashes and the close contact between dairy cows and dairy workers.
For more information on Leptospira in humans visit Leptospirosis – Better Health Channel.
To minimise the risk of leptospirosis in a herd:
-Vaccinate: This should be given in accordance with the manufacturer’s guidelines.
-vaccinate calves twice (as per vaccine directions);
-all adult cattle on the property should receive a booster annually;
-vaccinate pregnant cows at dry off, this allows for immunity to be passed onto the calve which lasts 6-12 weeks, as long as they consume enough colostrum;
assume all bought-in stock are unvaccinated and vaccinate on arrival with two injections of leptospirosis vaccine four to six weeks apart.
-Herd management: control rodents, as they are important vectors and readily spread the disease;
-keep areas around milking sheds well maintained to prevent stagnant water settling;
-fence or keep stock away from effluent ponds, sumps and waterways.
Producers are required to notify Agriculture Victoria within seven days if a confirmed case of Leptospirosis occurs on farm.
For more information on how to reduce the risk of leptospirosis in a herd contact a veterinarian or Agriculture Victoria on 136 186.