Beef cattle production and management
Practical Action
Occurrence
It can occur at any time of the year but most cases are seen in spring and summer. Young stock
between the ages of 6 months and 3 years are most affected. Animals in good body condition are
most affected. Mortality rate with blackleg approaches 100%.
Clinical Signs
Onset is rapid with the animal showing the following symptoms:
Lameness, depression and fever.
Limb muscles are swollen and painful. Gas formation under the skin can be felt over the
affected muscles and is referred to as crepitations
The animal becomes recumbent and usually dies
The disease can also cause sudden death.
Postmortem
It is not advisable to open up a carcass suspected to have died of the disease. Bloating and
putrefaction occur quickly. Affected muscles are dark red discoloured and spongy with an excess
of thin blood-stained fluid containing gas bubbles. AI.I body cavities contain excess fluid. The
spleen is swollen and firm. Haemorrhagic patches are present on most internal organs surfaces.
Diagnosis
Clinical signs and postmortem findings
Bacterial agent can be identified on blood smears and other organ smears
Treatment
It is rarely successful, but high doses of antibiotics can be tried during the initial stages of the
disease.
Control
Annual vaccination of animals at risk
Carcasses of animals should not be opened up but should be destroyed by burning or deep
burial to avoid soil contamination.
Anthrax (Tungundu, Chigwadara)
Anthrax is a zoonosis - that is it can spread between animals and man. Man get the infection via
the skin, inhalation or through ingestion of contaminated meat. It is caused by a bacterial agent
that can form spores.
Occurrence
Outbreaks tend to occur in either marked climatic or ecological change such as heavy rainfall,
flooding or drought.
Clinical Signs
Sudden death
The peracute form is characterized by: staggering, dysponea, trembling, collapse, convulsive
moments and death
The acute form is characterized by: fever, excitement followed by depression, stupor,
respiratory distress, convulsion and death.
Due to fever rumination ceases, milk production reduces and pregnant animals may abort
Chronic infections are characterized by oedematous swellings under the skin that can
be extensive involving the ventral neck, thorax or the shoulders
Treatment
Due to shortness of illness it is difficult to mtreat the condition, however the disease can bent
reated by penicillins.
Control
Vaccination
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