Leptospirosis in Cattle
Infection is associated with milk drop, abortion, weak calves and reduced fertility. As well as
transfer from cattle, to cattle, it can be transferred to humans causing flu like illness. (This is
a different type to Weil’s disease, which is carried by rats.)
Clinical Signs

Sudden milk drop in the infected animals. (Rare sign)

Affects all four quarters while the udder appears soft and flabby. The milk can have a
high cell count but no bacteria and can appear colostrum like.

Some of the affected cows will have high temperatures.

The milk drop will usually last up to about 6 days.

Abortion can occur 4 – 12 weeks after the milk drop (after infection).

The abortion will usually occur in the second half of the pregnancy.

If the dam becomes infected close to calving, the calf is usually born alive and weak.

Leptospirosis has more often been associated with reduced fertility with increased return
to services.
Diagnosis

Blood samples can be taken in order to assess individual animal’s status.

In the abortion cases - testing of the aborted calf is imperative.

Bulk milk samples to assess the herd’s level
Treatment
If infection is confirmed by ourselves, antibiotics can be used to treat infected animals.
Dihydrostreptomycin is used in large doses but this has a milk withhold. This regime can be
used in bought in animals of unknown status as well as those experiencing milk drop.
Prevention
There are three main ways in which to prevent the infection entering the farm. Not all of
which are always practical....
1) Fence off all contaminated water sources, all natural water sources should be assumed to
be infected.
2) Any bought in animal should be isolated, their status checked and vaccinated. Or they can
be treated with antibiotics when in isolation. This includes stock bulls.
3) Avoid contact with sheep (including co grazing) which can act as reservoirs of infection.
Vaccination is the most practical means of controlling the disease and preventing its spread
especially on infected farms. It will also reduce the risk of infecting farm staff. Please speak to
us at the practice about vaccinating your herd or any other query about this topic.