Clostridial diseases are caused by bacteria of the genus Clostridium. They form highly resistant spores that can survive in the environment for very long periods. They are also present in the gastrointestinal tract and as spores in tissues of healthy animals and become a problem with dietary stress3, injury and low immunity. Not all species of clostridia cause disease, but those that do are usually fatal.1
Clostridial diseases are known to have a high prevalence rate and high mortality, being in most cases by sudden death, and causing significant economic losses, since they can occur at any time of the animal's life.
The bacteria of the genus Clostridium are widely distributed in the environment, and normally inhabit the gastrointestinal tract in both animals and humans. These bacteria are anaerobic, it means, they develop in total absence of oxygen, and have the ability to sporulate to spread and remain dormant in the environment (soil, water and food), which makes them very resistant over time.
The pathogenic capacity of Clostridium is related to the production of several types of toxins, which can generate a decrease in oxygenation and cell death, causing extensive necrotic lesions and bacterial proliferation.
There is a wide range of clostridial diseases, where more than one genus of clostridium is usually involved: Enterotoxaemias (C. perfringens, C. septicum, C. sordellii, C. difficile), Tissue infections such as Symptomatic Carbon - Gas Gangrene - Malignant Oedema (C. sordellii, C. septicum, C, novyi A, C. chauvoei, C. perfringens A) and Black leg disease (C. chauvoei); and Neurotoxicosis (C. tetani and C. botulinum).
Enterotoxaemias can occur in young animals, associated with stress, low passive immunity, ingestion of the pathogen in the first few days of colostrum feeding, ingestion of protein-rich diet in a protease-deficient intestinal tract, inconsistent feeding practices.3 In adult animals, they usually occur due to changes in diet with an inadequate balance between fiber and forage that change ruminal pH and rumen acidosis.4 In both cases there is an increase in bacterial proliferation in the intestine causing tissue necrosis and toxemia.
In the case of tissue or histotoxic clostridial diseases, the bacterium, which is a normal inhabitant or is introduced traumatically, multiplies in the tissues, producing toxins and generating a local reaction. The toxins, when they reach the bloodstream, generate toxemia.
Enterotoxaemia is caused by proliferation of Clostridium perfringens. A number of toxins are produced in the intestine, but the most important toxin damages blood vessels and the nervous system. The disease tends to occur in young, rapidly growing animals in good condition and on a high plane of nutrition (lush growing pasture, young cereal crops and grain).1
There are 3 types of Clostridium that can produce different diseases of tissue type, such as C. sordellii associated with Gas Gangrene, C. chauvoei that causes Black Leg disease, and C. septicum associated with Malignant oedema.
Bacterial isolation and bacteriological characterization are essential elements for the diagnosis of each type of disease associated with Clostridium. Immunofluorescence and immunohistochemistry tests may be used.
It is important to have adequate sanitary and nutritional management, avoiding sudden changes in feeding specially with fiber, and improving hygiene practices in herds.
Given the high prevalence of clostridia in cattle and sheep, it is of great importance to carry out a control based on vaccination, which should at least be carried out twice a year.
Vaccination is the most effective way to control the disease, since generating humoral immunity results in the neutralization of toxins produced by this type of bacteria.
1 Robson, S. Clostridial disease in cattle. NSW DPI. Australia. http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0013/111163/clostridial-diseases-in-cattle.pdf
2 Popoff MR and Bouvet, P. Clostridial Toxins. Future Microbiol. 2009 Oct;4(8):1021-64.
3 McGuirk, S. 2015. Managing Clostridial Diseases in Cattle. University of Wisconsin, School of Veterinary Medicine, 2015 Linden Drive, Madison, WI 53706. https://www.vetmed.wisc.edu/dms/fapm/fapmtools/7health/manage-clostridial.pdf