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Clostridium bacteria are responsible for diseases such as black quarter, malignant oedema, uterine gangrene and gas gangrene. The infection of animals usually leads to acute mortalities, and the bacteria are widely distributed throughout South Africa. It can remain dormant for long periods before it strikes, and has caused the death of thousands of cattle in South Africa.
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Stockfarm spoke to the well-known veterinarian, Dr Faffa Malan, to find out more about one of these diseases, namely black quarter.
According to Faffa, black quarter is a common disease in cattle but is also found in sheep, although to a lesser extent. There is actually no run-up to the disease. “Animals that may look healthy today, are simply found dead in the camp the next morning. The bacteria especially target growing animals – in good condition and feeding on good grazing – between the ages of nine months and two years.
“The spores of Clostridium chauvoei, which cause the disease, can remain dormant in the animal’s body for months. When the animal suffers an injury in its large muscles, such as the hindquarters, thighs and shoulders, the spores increase and produce toxins and gas that can cause mortalities. In sheep and goats, wounds tend to become infected after shearing or lambing.”
Spread of infection
Faffa explains that the spores of the bacteria occur in soil and water – the animal, therefore, ingests it via feed and water. It can also spread to an animal’s muscles through small cuts in the mouth caused by roughage and shedding of teeth. The spores are then carried to the muscles in the bloodstream, where they remain dormant.
He says it is still not clear how the bacteria are activated, but muscle injuries definitely play a role. “Interesting though is that animals that died of black quarter become the largest distributor of the bacteria. The spores can remain dormant in the soil for long periods until it is picked up by an animal. Fortunately, it is not transmitted from one animal to another.”
General symptoms
Black quarter is seemingly a seasonal disease as it occurs mainly in summer and autumn, and after good rainfall. Another veterinarian, Dr Marijke Henton, says the soil on which the animals feed and are kept also plays a role.
“Because the disease can lead to sudden mortalities, live animals do not exhibit symptoms. Some of the symptoms detected by veterinarians are a higher body temperature, poor appetite, weakened digestive systems, and lameness. The swollen parts, especially on the large muscles, will become spongy at first and later grow cold and numb.
“Post mortems usually reveal a rapidly bloating and decomposing animal carcass. It also has a rancid butter flavour. Moreover, there is usually bloody foam around the animal’s mouth and anus, and the affected muscles contain gas and are dark red in colour,” she says.
Prevention and treatment
Chances of treatment are limited, says Faffa, and therefore the animals must be immunised on time. A wide variety of vaccines are available against black quarter – single as well as multi-clostridial vaccines.
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“If mortalities occur even after the vaccine was administered correctly, and after first-time vaccinations were followed up by a booster dose, one will have to ask a veterinarian to investigate. Smears from the liver and muscle lesions must be sent to a laboratory for examination and confirmation of the diagnosis. The correct vaccine can then be administered.
“If there is an outbreak on a farm, all susceptible animals that may be in the incubation period of the disease can be treated with antibiotics,” he says.
Faffa emphasises the importance of immunising all animals against black quarter every year, as well as against anthrax and botulism. – Stockfarm, Koos du Pisanie
For more information, phone Dr Faffa Malan on 082 908 8666.
