Blackleg ( latin Gangraena emphysematosa ) is a non-contagious, acute and highly feverish, sometimes enzootic extending animal disease . The causative agent of the disease is the anaerobic spore-forming bacterium Clostridium chauvoei . The spores of this bacterium are very resistant to environmental influences and can therefore survive in the ground for a long time. Typical intoxicating areas that are mostly known to farmers are in Lower Saxony and in some valleys of Upper Bavaria.
Cattle, sheep and goats in particular are at risk, the death rate in infected animals is very high and they usually die within a day. The meat of the dead animals cannot be used.
The natural source of infection for the animals to be infected is food or water that is contaminated with spores of the bogus pathogen, or wound infections. Therefore, there is an increase in cases in the summer months with grazing. The incubation period is 1 to 5 days.
In veterinary medicine , no distinction was made between intoxicating and anthrax . In 1876 Johann Feser and Otto von Bollinger published that the intoxication is caused by a different pathogen than the anthrax. In 1887 the microbiologist Saturnin Arloing was able to identify this pathogen and named it as Bacterium chauvoei after his teacher Auguste Chauveau . As a result, he also developed the first vaccine against the disease. In 1928 the name was changed to Clostridium chauvoei by Scott.
Pathogenesis and Clinic
The spores are absorbed from the feed via microlesions in the intestinal epithelium. In this way, these get into the skeletal muscles in a lymphogenic and hematogenic manner, where they germinate. The bacteria excrete toxins and enzymes that destroy the tissue and also produce gas. So-called gas edema develops, which shows a typical "crackling" when palpating. These are initially hot and painful, but quickly become cool and insensitive to pain. As the toxin continues to be released, death occurs quickly.
Clinical suspicion exists with typical palpation findings. The pathogen can be detected from contact samples of the changed muscles using immunofluorescence tests.
In the early stages, penicillin and surgical creation of aerobic conditions may help . Overall, the prognosis is very bad.
There is an obligation to notify and slaughter for infected animals .
- Studies on the so-called intoxicating beef. Journal for practical veterinary sciences, Volume IV, No. 1, Jan. 1876, pp. 13-26, no. 3, March 1876, pp. 103-122.