Leptospirosis (Lepto) in cattle is caused by a bacterial infection, there are various strains of Lepto in the UK, the most common of which is L. Hardjo. Lepto is a zoonosis (a disease which can affect people) so every effort should be made to know your disease status on farm and minimise the risk of transmission.
Spread
Once cattle are infected, they can shed bacteria for months and years. Shed is routinely through the urine but is also through semen.
Risk Factors
- buying animals in
- sharing bulls/ hiring bulls that are not routinely tested
- co‐grazing with sheep
- access to stagnant water and watercourses
Clinical Signs
The bacteria tend to localise in the kidneys and reproductive tracts of cattle so can cause fertility issues and abortion. In naïve cattle it can cause a syndrome known as ‘flabby bag’ with a drop-in milk yield, mastitis and pyrexia.
Diagnosis
A bulk milk test can be done to check for antibody levels in a non-vaccinated herd. If antibodies are present then it shows the cattle have been exposed to Lepto and control should be undertaken.
Individual animals or beef animals can be blood tested to check for antibody levels.
All abortions should be routinely tested and the presence of Lepto in these aborted foetuses can be detected.
Treatment
Indiviually affected animals can be treated with antibiotics and anti-inflammatories to enable them to clear the infection quicker but herd treatment would obviously be very time consuming and costly.
Control
In a positive herd there are various test and cull policies that can be adopted if you want to become accredited disease-free but the most practical control method is to vaccinate. There are a number of Leptospirosis vaccines licensed for use in cattle which give a good level of control. The vaccine protocol should be started in heifers prior to first breeding (and as a gold standard before their first turn out)
In a naive herd regular bulk milk monitoring for antibody levels should be carried out to monitor introduction of disease. If biosecurity can’t be truly secure, then vaccine should be considered as if disease does enter the herd then the result can be devastating.
Zoonoses
Lepto is a disease which can spread to people so owners of herds should take every precaution that disease is not transmitted to their workers. The disease in humans is usually seen as flu‐like symptoms, headaches and muscle pain. If any of these symptoms are seen in your workers then make sure a doctor is seen as soon as possible.
