PREVENTING LEPTOSPIROSIS: PROTECTING YOUR CATTLE & YOUR FAMILY

Article by Zoetis Australia

With an increased vigilance around zoonotic diseases (diseases which transfer directly from animals to humans), it’s worth reviewing the key reasons cattle producers are utilising Ultravac® 7in1 to protect the workforce on their farm.

In the human version of the disease, leptospirosis (also known as “lepto”) causes flu-like symptoms with a high proportion of people requiring hospitalisation. My father, David Petersen, caught the disease while calving a cow on a dairy farm near Finley NSW. He spent several days in hospital, with a severe fever and headache. With the aid of a good doctor, who recognised the signs early and initiated antibiotics, he recovered quickly. Unfortunately, the diagnosis of leptospirosis is not always achieved quickly, and treatment can be delayed. This can be a reason that people report chronic flu like symptoms for some time after infection.

The disease is contracted both in humans and cattle through direct contact with infected urine, placental material or contaminated water. The bacteria enters the body through mucous membranes of the eyes and mouth or damaged skin.

Human infections can occur:

• While assisting during calving without proper protection

• From urine splashing from infected cows during milking or calving

• Indirectly via contaminated water, food or soil

• By handling an aborted foetus or afterbirth

• Through contact with floodwaters

Leptospirosis affects beef and dairy cattle. The bacteria can live in the environment for months in moist conditions before infecting an animal. It can also survive for a long time in stagnant water and can spread over large areas in floodwaters. Once infected, cattle can subsequently shed Lepto in their urine. In the case of L. hardjo, cattle can shed lepto for periods greater than 12 months after their initial infection.

The consequences of infection in cattle are infertility, abortion and weak calves. Lepto can cause a form of mastitis where cows show a sudden drop in milk production and high cell count, with any milk produced potentially going a yellow colour. This can happen in an individual cow or group of cows, often in the absence of other clinical signs.

Cattle are a host to two common species of Leptospira, Leptospira borgpetesenii serovar Hardjo type Hardjobovis, referred to as Lepto hardjo for short,and Leptospira interrogans serovar Pomona, which is generally shortened to Lepto pomona.Most readers would commonly skip straight over the scientific name and not realise that different vaccines contain different species of Lepto hardjo, which cause different responses to the vaccine in cows.

Ultravac® 7in1 contains the above two strains of Lepto hardjo and pomona which have been sourced locally and is manufactured in Australia. The Australian Lepto hardjo strain used in Ultravac® 7in1 elicits a strong cell mediated immune response which is necessary to prevent infection of the kidneys of cows and subsequent urinary shedding. When used prior to natural exposure, Ultravac®7in1 prevents urinary shedding of Leptospira, breaking the cycle of infection in cow herds and stopping the spread of new infections.

Ultravac®7in1 can be given to calves from as early as 4 weeks of age and the vaccine works in the presence of maternal antibodies. Other vaccines only work to minimise shedding and can only be given to older calves after maternal antibodies have worn off, providing an opportunity for infection to occur. Given only a tiny number of bacteria are required to cause infection and disease in both cattle and humans, Ultravac®7in1’s unique mode of action is the only way to stop new infections occurring and clear the disease out of the herd. By preventing urinary shedding of Lepto, you will also be providing a safe workplace for staff.

To provide protection to cattle, it’s essential to begin vaccination early in life. Figure 1 gives a good representation of this:

Figure 1 – Vaccination requirements of cattle

Ultravac® 7in1 also protects against the 5 key clostridial diseases affecting cattle in Australia – tetanus, blackleg, enterotoxaemia, malignant oedema and black disease.

Zoetis recommends Ultravac® 7in1 as the core vaccine for cattle. It’s simple to implement and highly effective.

Article written by Dr Matthew Petersen BVetBiol, BVSc is a Veterinary Operations Manager at Zoetis. He has extensive clinical experience in mixed animal practice and lives in southern NSW.