There are three standard CHECS programmes for Leptospirosis; Accredited Free (AF) Programme, Monitored Free Programme, and Eradication Programme.
Full rules are detailed in the CHECS Technical Document.
Leptospirosis is a serious yet common cattle infection causing poor fertility, abortion, stillborn or weak calves and poor milk yields. It is also known as ‘flabby bag’ or ‘milk drop syndrome’.
Leptospirosis is a zoonosis, which means it is transmissible to humans from animals. It is a notifiable disease in man, and farmers/farmworkers, abattoir workers and vets are most at risk.
Infection in humans is usually from contact with urine (splashed on the face during milking) through placenta material, aborted foetuses, or through contaminated water. Humans experience flu-like symptoms with headaches and fever, and, very occasionally, meningitis.
In the first phase of Leptospirosis infection in cattle, the bacteria localise in the urinary tract, the udder and kidneys. Early symptoms often go unnoticed.
In acute cases, one of the most common signs may be a sudden drop in milk yield, 2-7 days after infection. The udder can become soft and flabby with colostrum-like secretions or blood-tinged milk in all quarters. Signs may, however, be mild and go undetected but some cows become lethargic and stiff with a fever and reduced appetite. Recovery can take up to 10 days.
In herds exposed to Leptospirosis for the first time, up to 30% of the cows may abort. In herds where the disease is endemic, the figure is closer to 5%. Abortion usually occurs 6-12 weeks after initial infection. Infection in late pregnancy can result in premature or weak calves being born that may die within hours of birth.
Poor fertility and low pregnancy rates are further signs that Leptospirosis may be present.
Leptospirosis is a difficult disease to eradicate as some cows can become carriers, as indeed can sheep, so mixed grazing is a factor. Cows shed the bacteria in their urine, which serves as a source of infection for other animals. Leptospires can survive for several weeks in wet soil, stagnant water and slow moving water-courses.
Controlling the disease relies on implementing and maintaining strict biosecurity to reduce risk of infection, on strategic treatment with antibiotics and on vaccination. Heifers must be vaccinated with a primary course, certainly well before their first pregnancy and a fortnight before turnout. Cows should be given boosters in spring, two weeks before turn out onto grass.
Aborting, or acutely affected animals should be isolated and treated.
Wildlife can be vectors for transmission so controlling pests will help reduce disease transmission.