Leaflets. Nos. 101 to 200 / Board of Agriculture and Fisheries.

  • Great Britain. Board of Agriculture and Fisheries.
Date:
1919
Catalogue details

Licence: Public Domain Mark

Credit: Leaflets. Nos. 101 to 200 / Board of Agriculture and Fisheries. Source: Wellcome Collection.

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    Post Mortem Appearances. In cattle the carcase is usually very distended with gases, and blood-stained froth may be discharged from the mouth, nostrils, and anus. Asarule the characteristic swelling is also present. When pressed, the swelling emits a crackling sound due to the presence of the gas, and if it is cut, a blood- stained fluid, possessing a typical rancid odour, distinct from the putrid odcur given off by a decomposing carcass, exudes from the cut surface. Owing to the formation of gas the muscular tissue appears to be dark red, almost black in colour, and porous looking. The blood in the vessels clots and is generally normal in appearance. In some cases lesions are absent in the superficial muscular tissues, but they are usually to be found elsewhere in the carcase. In sheep the muscular lesion is the same as in cattle, but it is not so noticeable. It may be found almost anywhere in the carcass, but is usually present in the upper parts of the limbs. On a close examination of the carcass of a sheep which has died of blackquarter it will usually be found that some part of the carcass is swollen; the fleece overlying the swollen portion pulls away easily, and the skin so exposed is of a dark purple colour. The characteristic crackling of gas is heard if the swollen part is pressed, and if the swollen part is cut into, the appearance is identical with the cattle lesion. Even in districts where blackquarter is prevalent, stockowners should always bear in mind the possibility that an animal which has died after a short illness, or has been found dead, may have died of anthrax. If an animal has shown symptoms of blackquarter during life, and the characteristic swelling distended with gas is also present after death, stockowners would be justified in forming the opinion that death was due to blackquarter, but, if these eharacteristic signs are not present, it is possible the animal may have died of anthrax. Infective Material and Method of Infection. The spores may remain active in the soil for years, but their number may be added to by material from new cases, especially if infected carcasses have been cut up on the pastures. The flesh or fluid of the swellings contain highly infective material, and the same applies to the blood-stained discharges. Animals do not infect each other directly, but pick up infection from the soil either by swallowing infected food or by contaminating a wound. Prevention. As the spore is capable of living in the soi], the greatest care should be exercised to prevent any addition to the number of bacilli already in the soil by the careless disposal