88 Journal of Agriculture, Victoria. [lo Feb., 191 2. 



of an anthrax animal is heated for half-an-hour at 212 degrees F. to 

 destroy the germs ; it is then washed with boiled water to dissolve out 

 the toxins, and the resultinjj solution is injected in doses of 2 to 4 c.c, as 

 the protecting virus. The advantages claimed are: — {a) That the material 

 can be prepared on the spot when dealing with an outbreak ; and {b) that, 

 as the germs are destroyed, the risk of inoculating virulent anthrax or 

 introducing it to a new area is avoided. 



BLACKLEG. 



Synonyms : — Black-quarter — Quarter-Ill — Sym-ptomatic Anthrax — 

 Enifhysematous Anthrax. 



Definition. — An acute infectious febrile disease, affecting almost 

 solely young cattle, cau.sed by the bacillus Chauveauii and characterized by 

 fever, lameness and hot, painful swellings on the quarter, thigh, neck, 

 shoulder or elsewhere which tend to become emphysematous and gan- 

 grenous. 



This disease has only becom.e prominently prevalent throughout Aus- 

 tralia during recent years. It is a disease so common in England that 

 it would be well known to imported veterinarians, and its occurrence would 

 scarcely have escaped their notice, yet it was not till the late nineties that 

 its existence was chronicled. Since then it has been the cause of con- 

 siderable mortality amongst calves and young stock in many dairying 

 districts. The incidence of the disease is practically confined to young 

 cattle between the age of three months and two years. It seldom-, if ever, 

 attacks calves while still on a milk diet solely ; this because of the fact 

 that the germ is usually introduced from the soil when grazing. 



Nature and Causation. — For a long time blackleg was looked upon 

 as a modification of anthrax but it is now known to be caused by a dif- 

 ference bacillus, and while it has many features of an anthracoid character 

 its clinical history, local symptoms and age period of incidence serve to 

 easily differentiate it from true anthrax. 



The actual cause is a bacillus, called the bacillus Chauveauii or bacillus 

 anthracis emfhysematosus, having the following features : — Rod-shaped 

 with rounded ends one end being often larger than the other on account 

 of the presence of a spore, so making the bacillus club-shaped. It is 

 anserobic, living in the tissues without utilizing the oxygen of the blood 

 and being but rarely found in the blood in which oxygen is abundant; 

 motile, the movements being both undulatory and rotary; and sporulates 

 within the body. It withstands putrefaction, and is found abundantly 

 in the tissues a long time after death, even up to six months. A refer- 

 ence to the description of the anthrax bacillus will show that in regard 

 to all the features just mentioned the bacillus of blackleg is the direct 

 antithesis of the anthrax bacillus. Like the latter, however, this bacillus 

 persists in the soil for an almost indefinite period, and blackleg can be 

 readily produced by inoculating the washings of marshy soils that have 

 been contaminated a long time previously. The disease occurs under the 

 same conditions and on the same class of country as anthrax. An obvious 

 preventive measure, therefore, is to avoid depasturing young cattle on wet 

 clayey or marshy soils during the age period of this disease. It would 

 seem to be necessary for there to be wonnds or scratches of the mucous 

 lining of the mouth or alimentary tract before the disease can be con- 

 tracted, for it is probably only conveyed by inoculation. In this connexion 



