The clostridial group of diseases are caused by clostridial bacteria. It is important to understand that these bacteria are anaerobic, spore-forming organisms. This means the organisms do very well in a low oxygen environment, such as tissue material and organic matter, and that they can survive for long periods in a dormant state as spores. Once they find themselves in a highly favourable environment, they will multiply rapidly and release harmful toxins that will wreak havoc.
The so-called triggers of clostridial diseases include factors that put stress on the animal. These may include a sudden drop in feed quality, poor management, highly stressful circumstances, and any factor that places stress on the animal’s immune system. The fact that this is not a single disease, but rather a group of diseases, makes it a complicated matter. According to Dr Johan Cloete of MSD Animal Health, this group of diseases can be better understood when it is divided into three groups: gangrenous, enterotoxigenic, and neurotoxic. “It is very important that both the farmer and veterinarian understand the differences between the various clostridial diseases and that a diagnosis is confirmed by a post mortem and tissue analysis. It is easy to step into the trap of over-simplifying these diseases. Careful distinction is therefore needed to ensure accurate preventative treatment and vaccination. Dr Cloete describes the three groups as follows:
Symptoms of diseases in this group include rapid necrosis (tissue death). This can occur with or without the presence of gas, the latter being worse. Some of the most important diseases in this group are blackquarter, swollen head (dikkop), malignant oedema and uterine blackquarter.
The most important symptom of diseases in the second group is intestinal inflammation, which leads to several other problems. Some of the most important diseases in this group are pulpy kidney, enterotoxaemia and lamb dysentery.
The third group of diseases attack the nervous system and is characterised by stiffening or paralysis of the muscles. Some of the most important diseases in this category are tetanus and botulism. If an animal is affected by tetanus, explains Dr Cloete, it will often die suddenly due to a lack of oxygen or heart failure. In the case of botulism, or lamsiekte as it is known in Afrikaans, the muscles become paralysed and the animal will lie down. It cannot eat and drink and can asphyxiate.
Treatment and prevention
Clostridial diseases are quick to attack and there is usually nothing to be done once it is observed. “It is usually too late to administer an antitoxin, and antibiotics have no effect on the toxins released by the clostridial bacteria. In most cases euthanasia is the most acceptable path to follow.” Prevention is always better than cure. In the case of clostridial diseases, correct and disciplined vaccination is the only option available to prevent outbreaks. This can, of course, be supported by good management practices, ensuring healthy immune systems in the animals, and avoiding disease triggers. It is important that the necessary steps are taken after an outbreak and mortalities investigated to determine exactly which clostridial disease was the culprit. – Marike Brits, Stockfarm
This article is the eighth in a series of informative animal health articles. The series goes hand in hand with the #VideoVet video series that can be viewed on www.agriorbit.com. Watch the video below.
For more information, contact your MSD Animal Health representative or phone 011 923 9300. (ZA/ORUM/0218/0003e)
Thank you for the support of several role-players in creating this series: the Gauteng Department of Agriculture and Rural Development, Dr Gillian Declercq and the CCS veterinarians (Dr Dzunisani Ngobeni, Dr Lindsay Parvess and Dr Heidi Kuhn), MSD Animal Health, as well as Kenneth Ndlovu and the Amogelang team for their assistance and animals for demonstration.