lo Feb., 1912.] Diseases of Farm Animals. 83 



DISEASES OF FARM ANIMALS. 



Anthrax and Blackleg. 



Ill response tu many enquiries for information concerning the above named 

 diseases, the following article by Dr. S. S. Cameron, M.R.C.V.S., is reprinted 

 from the Journal of Agriculture for July, 1906. — Editor. 



ANTHRAX. 



Synonyms : — Cumberland Disease — splenic fever — splenic apoplexy — 



black rot. 



Anthrax is the most ancient contagious disease of animals that is 

 known. The sixth plague of Egypt, referred to by Moses, was anthrax, 

 and elsewhere he indicates the transmission of the disease from cattle to 

 man by means of soiled clothing. Homer, Ovid, Plutarch, Dionysius, 

 Livius and other ancient writers frequently refer to this disease ; and in 

 some cases their descriptions are most exact and plainly manifest the 

 disease as we know it now-a-day=. 



Anthrax exists in most countries of the world and has been prevalent 

 throughout Australia for a long period, affecting cattle and sheep prin- 

 cipally but horses and pigs in les.ser degree. In New South Wales it 

 was known prior to the seventies as Cumberland Disease (from its 

 particular prevalence in the County of Cumberland) and the credit of 

 definitelv identifying and announcing this disease as anthrax belongs 

 to the late Graham Mitchell, F.R.C.V.S., of Melbourne. Early in 1876 

 there was great mortality of sheep in the Western District of Victoria 

 which was recognized as being analogous with Cumberland disease and 

 identified by Mitchell as anthrax. His announcement was, however, 

 officially discredited, much bitter feeling being engendered, and it was 

 not till after Mr. Mitchell's death in 1888 that the correctness of the 

 diagnosis was publicly admitted. A detailed history of the controversy 

 on the subject, which was a lengthy one, is given in a brochure on 

 " Cumberland Disease in Australian Sheep " published by Graham Mitchell 

 in 1877. 



Definition. — An acute contagious febrile blood disea.se. affecting her- 

 bivorous and omnivorous animals (including man) principally, caused by 

 the bacillus anthracis, and characterized by a general haemolysis with 

 engorgement of the spleen and other organs and by sudden on.set, rapid 

 ■ course and almost uniformly fatal termination. 



Causation. — The bacillus anthracis was discovered in the blood of 

 animals dead of the disease in 1850 by Davaine, and was demonstrated by 

 him to be the specific cause of the disease thirteen years later (1863). It 

 was the first disease-producing organism to be recognized, and the science 

 of bacteriology may be said to date from its di.scovery. Usually, but not 

 without exception, it is found in the blood of all parts of the body and 

 in the spleen and other organs. Compared with others since discovered 

 it is a large bacillus (5 to 20 microns long by i to 1.15 microns thick) 

 and is distinctly rod-shaped with square ends. It is non-miOtile, serboic, 

 stains by Gram's method or any aniline dye and grows freely on a variety 

 of culture media. Grown outside the body it assumes a filamentous form 

 and bears spores which are particularly resistant to extremes of tem- 

 perature. 



• A micron equaU o-^Vnn P-'*''* of an inch. 



