50 ^^ Blackleg. 



and the conrse, as a rule, is slower. In subcutaneous emphy- 

 sema, leaving out of consideration the etiological factors, the 

 total absence of acute symptoms of inflammation and the normal 

 condition of the skin are characteristic. 



At the autopsy, aside from the microscopic results and 

 the serous-emphysematous infiltration in the region of the 

 swelling, blackleg is indicated especially by the odor of rancid 

 butter, the black discoloration of the musculature, and the 

 absence of a strictly acute tumefaction of the spleen. 



In doubtful cases the diagnosis is verified through microscopic examination 

 of the diseased muscles or the yellow foci in the liver and the kidneys, and through 

 injection of such material into test animals. For this purpose Wulff recommends 

 drying the piece of muscle in an air current at 30-32°C. and, after pulverization, to 

 heat the material 5 minutes in distilled water at 65°C. From a mixture made of 

 0.1 gm. of dried muscle substance and 10 cc. water, 0.002 cc. is sufficient to kill 

 guinea pigs by intermuscular inoculation. At the autopsy of such guinea pigs 

 numerous bacilli are found in the liver, which, however, never form chains (Foth; 

 forming of chains characterizes the bacilli as edema bacilli). On the other hand, 

 pigeons, rats and rabbits are never, or at least only exceptionally, killed by 0.01 cc. 

 of the emulsion. 



Owing to the extreme rarity of blackleg in other kinds of animals, the diag- 

 nosis should always rest upon an exact bacteriological examination, because, other- 

 wise, confusion with pseudo-blackleg and malignant edema is liable to occur. 



Treatment. The treatment of blackleg is hardly ever suc- 

 cessful and only consists in a local antiseptic treatment of the 

 swellings. For this purpose, it is advisable to incise the tumor 

 at several places and then press it out and wash the exposed dis- 

 eased tissue carefully and repeatedly with disinfecting liquids. 

 The most suitable for this are : 3% carbolic acid, 5% lysoformic 

 acid, 0.1% salicylic acid, 0.1% formalin solution, and tincture 

 of iodine, of which liquids the first ones should also be sub- 

 cutaneously injected at several places in the immediate sur- 

 rounding tissue. 



If the swelling has developed in the middle of an extremity, 

 a bandage or other ligature may be applied above the tumor, 

 and the latter may then be scarified (Wallraff). Tolstouchow 

 obtained good results from applications of ice and snow, and by 

 rubbing with oil of turpentine. 



Leclainche & Vallee recommend the treatment ^ith immune 

 serum, of which first 60 to 100 cc. are injected into the jugular 

 vein, and thereafter this amount is injected every 2d to 4th 

 hour under the skin in the region of the shoulder. In the be- 

 ginning of the infection and in cases of a protracted course, 

 the results are said to be favorable. 



Prevention. As the disease seems to be limited to certain 

 regions, and to certain places within those regions, especially 

 damp, swampy pastures, the cattle should be kept away 

 from such places. Through rational amelioration of the soil 

 (draining away the water, re.gulating the rivers, planting trees 

 and plowing) places which have been considered dangerous 

 may be made harmless. In Denmark, according to Jensen, the 



