" BRAXY " SHEEP DISEASE IN AUSTRALIA. 595 



through the wounds. The disease is common on stations where braxy 

 or a similar disease has never appeared, and on many stations 

 where the latter is common malignant oedema (" blood-poisoning") 

 is unknown. 



In comparing the braxy disease with malignant oedema it 

 should be remembered that both morphologically and culturally 

 the two bacteria vary deirnitelv- An opportunity offered, how- 

 ever, to test the two by a very satisfactory method. 



A sheep which had been inoculated with a malignant cedema 

 culture and gradually recovered after being very ill for two days, during 

 which necrosis of the inoculated limb occurred, the necrosed tissue 

 ultimately sloughing, and healing of the wound finally taking 

 place, was inoculated a month after recovery with 0-25 cc culture 

 of the Tasmanian bacillus. The result was death in 30 hours 

 with the typical symptoms and post-mortem appearances, proving 

 that no immunity to braxy had been conferred as a result of the 

 attack and recovery from malignant oedema. (See Appendix A, viii.) 



Blackleg of cattle in many ways more approaches the sheep 

 disease. It has also a great preference for young animals in good 

 condition. The natural disease is very like the experimental 

 braxy, the bacilh are morphologically very like, and even in 

 cultures are in appearance similar. Where blackleg is common 

 in cattle on many holdings, however, it has not been observed 

 that sheep are liable to a similar disease, and vice versa, holds good. 

 Although stab cultures in agar show a resemblance, yet separate 

 colonies are quite different, the braxy colonies being biconvex 

 discs, and not spherical. Further, sheep immune to braxy are in 

 no way immune to blackleg, as the following experiments show : — 



Sheep 20 and 31 which had been immunised to at least the 

 ordinary fatal dose used of both the Victorian and Tasmanian 

 bacilli (see Table 2) were inoculated each with 0"25 cc. first broth 

 culture from virulent dry blackleg muscle ; another sheep (27), 

 which had resisted feeding with virulent Tasmanian culture, as a 

 control received a similar dose. The typical course of experimental 

 blackleg in sheep ensued, the control sheep (27) dying in 54 hours, 

 sheep 31 in 60 hours, and sheep 20 in 70 hours after inoculation. 

 It is rather interesting to note that the post-mortem picture 

 presented in each of these cases was in many respects similar to 

 that of the braxy disease. The muscle lesion was more intense, 

 while the subcutaneous oedema was comparatively small in 

 amount, though still considerable. The abomasum mucosa was 

 congested throughout, with patches of a deeper, almost purple, 

 colour here and there. The sub-mucosa was distended with much 

 serous infiltration, causing thickening of the stomach wall to 

 nearly an inch in extent, this lesion being very definite in each 

 case. The intestines were also congested more or less throughout. 

 The liver and kidneys were congested. The lungs were oedematous, 

 and the pericardium distended with clear effusion. These lesions 

 are especially interesting in view of the fact that Blackleg is by 

 some considered not uncommon in sheep. 



