Blackleg and leptospirosis

Clostridial (mainly blackleg) and leptospiral (lepto) infections represent a risk after flooding. This is because moisture provides more favourable survival conditions and the blackleg spores are exposed by the effects of soil erosion or movement.


When blackleg spores or leptospiral organisms enter an animal, disease may or may not occur immediately. For blackleg, some other precipitating event, such as an injury, is usually required for disease to develop. Therefore, it may be some time before the disease is actually seen.

Blackleg generally presents as severe disease with sudden/rapid death in animals less than 2 years of age, with rapid bloating of the carcass. There may be gas under the skin or in the muscles even before death.

For leptospirosis, disease in young animals may occur soon after infection, especially if the lepto involved is like L. pomona, resulting in severe depression, high temperature and often blood in the urine. Lepto infections in older animals may be asymptomatic or result in abortions. Abortions due to lepto do not usually occur until the third trimester of pregnancy, so significant abortion numbers might not be seen until months later.


Vaccinations for both diseases are highly effective in preventing disease if a full course is given. Even if already infected, vaccination may prevent clinical leptospiral disease developing. The animal will remain infected and able to transmit disease organisms, though in reduced numbers. Several 7-in-1 formulations are available that enable you to vaccinate against both common leptospiral and clostridial diseases with one product. (There are many different leptospiral organisms but only 2 cause most lepto diseases in cattle.)

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