Leptospirosis

Dairy cow with leptospirosis

What to look for

  • Infected animals often do not show any clinical signs
  • NB - leptospirosis can cause a very serious flu-like condition in farm workers


Acute disease in calves:

  • High temperatures
  • Red coloured urine
  • Poor appetite and, in some cases death


Adult cows:

  • Abortion – usually in the latter half of pregnancy (foetus may be mummified)
  • Even if the infected animals do not show any signs of infection they can still be excreting organisms in their urine.

Cause

A bacterial infection (Leptospira). The two most important types of the Leptospira in cattle in Australia are hardjo and pomona. These organisms reside in the kidneys of infected animals for long periods (weeks or months) and are passed out in urine, which can remain infectious for weeks in moist conditions.

Animals likely to be affected

Calves

Calves may experience an acute infection that spreads readily and is characterised by red urine (“red water”), high temperatures, poor appetite and, if not treated promptly, can lead to death.

Adult animals

Occasionally, adult animals will develop a disease similar to that described for calves. Usually the infection causes no clinical signs, unless they are pregnant, when it may lead to abortion.

Other diseases with similar signs

  • “Red water” can also occur in tick fever or poisoning by kale or rape, or phosphorus deficiency.
  • Other causes of abortion – require a thorough disease investigation.

Confirming the diagnosis

Diagnosis requires identification of the Leptospira organisms in urine of infected animals or aborted foetuses. The Leptospira organism is hard to isolate in the laboratory and sometimes the diagnosis can be confirmed by showing a rise in Leptospira antibodies in blood samples taken during the course of the outbreak.

Spread of the disease

Animals become infected via pasture or bedding that has been contaminated by urine from infected animals, which may appear healthy but are secreting Leptospira in their urine.

Risks to people

People can contract Leptospirosis by contact with urine from animals that have the disease but may not be showing any signs of illness. Leptospirosis can make people very ill for weeks or months. There is currently no vaccine available to protect people against this disease.

Treatment

Antibiotics are effective. Consult your vet regarding the best form of treatment.

Risk factors

  • Failure to vaccinate young stock with a lepto vaccine
  • Inadequate vaccination - calves require two doses of vaccine six weeks apart early in life, followed up by booster doses

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