320 ACTIONOBACILLOSIS 



The skin is often affected. In the single specimen which the 

 writer has had an opportunity to study, the ray-like arrange- 

 ment of the organism and the tissue immediately surrounding 

 it, could not be easily distinguished from a section of actin- 

 omycosis. 



§ 242. Differential diagnosis. Actinobacillosis is to be 

 differentiated from actinomycosis, tuberculosis, perhaps cer- 

 tain parasitic diseases of the skin, and localized bacterial 

 infections. 



The diagnosis is made from the various locations of the 

 lesions. The more important of these is the apparent selec- 

 tion of the skin. The examination of the fresh pus does not 

 reveal the yellow granules as observed in actinomycosis but 

 when squeezed between two cover-glasses they are said to be 

 distinct. The actinobacillosis does not take the gram stain, it is 

 infectious for guinea pigs and rabbits, and it is readily cultiva- 

 ted on artificial media. It appears to be transmitted more 

 often in cattle by cohabitation than actinomycosis. 



The differentiation from any parasitic trouble is made by 

 the finding of the animal parasite. The nature of the lesions 

 and the finding of tubercle bacteria in the discharge by micro- 

 scopic examination, or by producing tuberculosis in guinea 

 pigs by inoculations, would differentiate it from tuberculosis. 



§ 243. Prevention. As the natural habitat of arfzwo^a- 

 cillose is not known, the source of infection is undetermined 

 and consequently effective preventive measure are not known. 

 The fact that it seems to spread from infected to healthy cattle 

 necessitates the isolation of the infected. It is more desirable 

 when possible to separate the well from the infected animals. 



REFERENCES. 



1. HiGGiNS. Actinobacillosis. Bulletin No. /, Biological Lab- 

 oratory, Department of Agriculture, Dominion of Canada, 1904. Also 

 Proceedings Amer. Vet. Med. Asso., 1904. 



2. LigniSres and Spitz. Actinobacillose. Contribution h 

 V tlude des affections connues sous le nom d'actinomycose. Buenos Aires, 

 1902. 



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