Farm Ireland
Independent.ie

Saturday 29 April 2017

Annual Lepto vaccination is essential for both man and beast!

Charles Chavasse

Leptospirosis is a highly contagious bacterial infection that can affect both the farmer and his cows.

In humans the infection can be acquired from infected cows by coming in contact with their urine. This could be as little as a flick in the face with a wet tail or urine splashing in the parlour.

Once affected, people may become tired, depressed or suffer from flu‐like symptoms. Infected cows and heifers show fertility signs including abortion, the birth of mummified calves, still births or the birth of weak calves. Dairy cows may also suffer from milk drop syndrome.

Leptospirosis is widespread in Ireland, with over 70% of dairy herds and approximately 80% of beef herds infected. In this country the disease in cattle is caused Leptospira Hardjo. There are two strains (types) within the Hardjo group, borgpetersenii and interrogans, which although genetically different are indistinguishable serologically i.e. it is not possible to tell these two stains apart on routine blood tests.

Once animals become infected, the bacteria colonises the kidneys and cattle may become carriers who shed the bacteria intermittendly in their urine and pass the infection into the environment and infect other cattle and their stockmen.

zoetis lepto graph.PNG Vaccination with Spirovac will both reduce the colonisation of the kidneys, so reducing the number of carriers in the herd and it will reduce shedding from those animals that are already infected, thus reducing the infectious pressure on the farm for the benefit of both man and beast.

Traditionally vaccination programmes started when heifers were about to go to the bull and the yearly booster was also given in the spring to the main herd.

This is a busy time of year, and now that Spirovac is available to vaccinate against Lepto hardjo, which provides 12 months duration of protection, the vaccine can be used when most convenient from a management perspective. E.g. it could be used at drying off.

Young heifer calves/weanlings can become infected during their first year, as the immunity they acquire with colostrum wanes by the time they are 12 weeks of age.

This should be prevented in an attempt to reduce the number of carriers in the herd. Spirovac can be used from 4 weeks of age, followed by a second dose 4 to 6 weeks later and an annual booster injection thereafter.

zoetis lepto dosing.PNG In conclusion, the control of Lepto depends on:

a) Reduced exposure to the disease

  • Maintain a closed herd where possible and don¡¦t buy in heifers or a bull
  • Ensure there are good boundary fences to keep other stock out
  • Use piped water, rather than open watercourses and do not co-graze with sheep, as sheep can be a reservoir for Lepto infection, maintaining the disease on a farm.
  • Minimise the infection reservoir through treatment, vaccination and/or culling of carriers

b) Increase immunity

  • Vaccinate breeding animals as early as possible before they are exposed to the disease. With Spirovac this can be done from 4 weeks of age.
  • Annual booster vaccination after initial course is completed. With Spirovac, the farmer is not restricted to boostering pre-breeding in the spring but can choose to vaccinate at a more convenient time of year.

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