LEPTOSPIROSIS

What is Leptospirosis and how do cattle become infected?

Leptospirosis is the name given to the range of diseases of animals and humans caused by the group of bacteria called Leptospira. Many such varieties are harbored by a wide range of animals and all of them are capable of causing illness in humans.Two Leptospirosis organisms causing disease in cattle in Australia are:

• Leptospira interrogans serovar pomona
• Leptospira interrogans serovar hardjo

For simplicity, these organisms will be referred to as Lepto pomona and Lepto hardjo.

The source of Leptospirosis is usually an infected animal which contaminates pasture, drinking water and feed with its urine. Wild animals may also transmit the leptospires if infected. Leptospires survive in infected animals for long periods of time and are spread via the urine. The organisms are capable of surviving in the environment for several months under favorable conditions. Leptospirosis occurs with warm moist conditions and is prevalent in higher rainfall areas and irrigation districts of Australia. It will occur in other areas during wet years.

How does Leptospirosis affect beef, dairy cattle and calves?
Lepto pomona and Lepto hardjo can both cause abortions and stillbirths in beef and dairy cattle and are associated with low calving rates and infertility in pregnant cows. Lepto hardjo primarily affects lactating and pregnant cattle while Lepto pomona can affect all cattle and calves. The disease caused by Lepto pomona is commonly referred to as 'redwater' due to the presence of broken down red blood cells in the urine. Calves as young as two or three weeks of age can become affected and severely affected animals may die. Redwater can occur in adult cattle, but these cases are less common and symptoms are usually milder and deaths are rare.

A distinctive form of mastitis may also be associated with Leptospirosis. There is a sudden onset of slackness of the whole udder and abnormal milk in all four quarters. Milk will return to its normal appearance after a few days.

Can humans contract Leptospirosis?
Yes. Humans can also become infected with Leptospirosis and this is a MAJOR RISK to people working closely with infected animals. Those at greatest risk include dairy farmers and others who work closely with cattle (e.g. veterinarians, graziers, abattoir workers and livestock agents).The risk of transmission to humans is an important reason for the control of leptospirosis in cattle. People that become infected with Leptospirosis become very sick and suffer a 'flu-like' illness including fever, muscular pain, headache, intolerance of light, vomiting and abdominal pain which can make the sufferer feel tired and 'washed-out' for up to 18 months.

How do people contract Leptospirosis?
Humans can become infected through handling aborted calves without gloves, by coming in contact with urine from infected animals that may enter the eye or nasal passages or through poor attention to personal hygiene, including washing hands after handling infected animals.

How can animals be protected When should calves be from Leptospirosis?
Immunisation is the most practical method of controlling leptospirosis in a cattle herd and helps prevent the possible transmission to humans.

Coopers Cattlevax LC 7 in 1* is a vaccine available from Coopers Animal Health for the protection of cattle from Leptospirosis infections caused by Leptospira interrogans serovars hardjo and pomona and minimises shedding of Leptospires. Cattlevax LC 7 in 1 also protects cattle against Enterotoxaemia (Pulpy Kidney), Blackleg, Malignant Oedema, Black Disease and Tetanus.

Cattlevax LC 7 in 1 is administered subcutaneously as a 4 ml dose to cattle.

A single dose of Cattlevax LC 7 in 1 will stimulate the production of protective antibodies in beef, dairy cattle and calves. A period of two weeks is required after vaccination before animals acquire a level of protection. Maximum protection is not achieved until the second booster dose is given 4-6 weeks after the first, followed by an annual booster.

It is recommended that the annual booster to pregnant cows be administered 2-3 weeks prior to calving to ensure maternal antibodies are transferred to the calf.

When should calves be vaccinated?

Cattlevax LC 7 in 1 is recommended to be administered to calves 4-6 months of age. Calves which have been born to correctly vaccinated cows and have had access to colostrum will receive maternal antibodies that will provide protection from Lepto hardjo and Lepto pomona in their first few months of life.

How important is urinary shedding?

Animals that are infected with Leptospirosis will excrete leptospires in their urine. Any control and prevention program for leptospirosis should be aimed at reducing the number of leptospires that are shed in urine and hence prevent the transmission of the disease from animal to animal or more importantly from animal to humans.

Cattlevax LC 7 in 1, like all current Cattle Leptospirosis vaccines in the marketplace can help minimise urinary shedding when used prior to natural exposure to the disease. It should be remembered that:

• Urinary shedding only occurs if the animal has or has had Leptospirosis
• All Leptospirosis vaccines prevent infection and hence help prevent urinary shedding, when used prior to exposure.
• No infection equals no urinary shedding
• Animals already infected with leptospirosis at the time of vaccination may still shed Leptospires in the urine for some months after vaccination, irrespective of which leptospirosis vaccine is used.

Correct Vaccination Technique and Instructions

Coopers Animal Health Vaccine Product Range - Product information and Spectrum of Efficacy