48 



Blackleg. 



In the meantime, pronounced respiratory distiarbanoes de- 

 velop, while the activity of the heart is accelerated (90 to 100 

 contractions a minute) and becomes weak. Sometimes attacks 

 of colic are observed. At last the animal lies on the ground 

 stretched out motionless, the temperature is lowered to 

 37-35° C. or rises once more, and then death follows immediately, 

 The disease generally lasts from % to 2 days ; in rare cases, 

 however, it may last from 4 to 10 days. 



The crepitant swelling mostly develops at one place, but 

 in some cases tumors appear at several parts of the body, grow 



rapidly and coalesce to 

 form a single large 

 swelling. 



If the swelling is de- 

 veloped in the deep 

 layers of the hip or 

 shoulder muscles, its 

 other properties can- 

 not be exactly deter- 

 mined, aside from tlie 

 increase in volume of 

 the involved part of the 

 body. The skin appears 

 relatively healthy, and 

 no crepitation is ob- 

 served on touch; how- 

 ever, by a stronger per 

 cussion, a hollow sound 

 may be observed in the 

 periphery of the swell 

 ing even in these cases 

 If the cavity of the 

 mouth or the throat is 

 the seat of the disease 

 sjanptoms of a severe 

 inflammation of the 

 throat are usually ob- 

 served whose specific 

 nature is indicated by the crepitation of the swollen parotid 

 region. Infection of the tongue is indicated by considerable 

 swelling, while the tip of the organ crepitates on touch and 

 projects from the mouth. In the extremely rare cases of 

 primary infection of the diaphragm, the cause of the fever as 

 well as of the difficult respiration can only be determined by 

 autopsy. 



According to Arloing, Cor-nevin & Thomas, and also Feser, black- 

 leg, especially in older animals, sometimes appears in a much milder 

 form. In such cases there may or may not appear a moderate, indis- 

 tinct swelling on any part of the body, the animals show moderate fever 



Fig. 17. Blaclcleg. Crepitating swelling of 

 the forehead and' submaxil- 

 lary space. 



