Biobest Laboratories Ltd

Leptospirosis

The Disease

Leptospirosis is caused by infection by two bacteria called Leptospira interrogans serovar hardjo, and Leptospira borgpetersenii serovar hardjo. These cause abortion, stillborn or very weak calves, poor fertility, and fever and milk drop. Leptospirosis can also affect humans, occasionally causing fatal meningitis.

The Effect in Your Herd

Your herd may experience reproductive problems such as failure to conceive and abortions, and calves born to infected animals are often sickly and weak.

The Route of Transmission

The bacteria are present in the reproductive tract and kidneys, and are shed in the urine of infected animals, in the semen and can pass into unborn calves. The organisms often pass into streams and other water sources in contaminated pasture; therefore piped water is safest for health scheme cattle. Vaccination may prevent some clinical disease, but does not prevent infection of the herd.

Disease & StatusAnimals to be testedAction required
1. Leptospirosis: First herd test

The whole herd over the age of 2 years is tested and all animals to be kept for breeding between 1 and 2 years old are to be tested.

If this test is clear, the test is repeated within 6-12 months to gain Accreditation test 2. If positive animals are found, these are removed*, and the next test is 3.
 2. Leptospirosis: Second herd test (if the first test is clear).

The whole herd over the age of 2 years is tested and all animals to be kept for breeding between 1 and 2 years old are to be tested.

If this test is clear, the herd becomes Accredited for Leptospirosis. Test as per 4 yearly to maintain Accreditation.
 3. Leptospirosis:Further herd tests (if the first test showed active Johne's infection).

The whole herd over the age of 2 years is tested and all animals to be kept for breeding between 1 and 2 years old are to be tested.

If positive animals are found, these are removed, and the next test is a repeat of 3, to be repeated yearly until a clear test is achieved.
 4. Leptospirosis:Maintenance of Accreditation A statistical sample (see Appendix B) of breeding animals 12 months of age or older must be tested, including the bulls (plus a quarterly bulk milk test for dairy herds).  Repeat yearly to maintain Accreditation.
 5. Dairy Milk Monitoring scheme Bulk milk tank sample; if more than one tank is present, a sample must be taken from each one.  Repeat at 3 monthly intervals.

*if too many animals require removal, there are other options, e.g. vaccination, which may be used, and this will be discussed in detail when the results are reported.