INTERNAL DISEASES 397 



Scarlet fever, which has always been regarded as peculiar 

 to man, appears from the observations of Siegel, previously 

 referred to, to be an exception. He describes a protozoon 

 similar to that of syphilis as the exciting cause of the disease. 



Diseases which are originally confined to animals, but which 

 may easily be transferred to man, are anthrax, glanders, rabies 

 and foot-and-mouth disease, which must be included among the 

 acute exanthemata. 



Anthrax, the spore-bearing bacillus of which was described 

 by Koch, is communicated to man partly by the blood of in- 

 fected animals being inoculated through cracks in the skin, and 

 partly by inhaling the dried bacilli and spores with the dust 

 from hides and wool. Symptomatic anthrax, which occurs in 

 cattle, sheep, goats, and occasionally in horses and pigs, is not 

 identical with true anthrax. 



Glanders is caused by the bacillus Mallei (Loffler) and 

 occurs primarily in horses, donkeys and goats. It is very 

 infectious for man, and also experimentally for guinea-pigs, 

 cats, hedgehogs, rabbits and field mice. 



The cause of rabies has not yet been isolated ; it is primarily 

 seen in wolves, foxes and dogs, though man and all domestic 

 animals may be secondarily infected, nearly always directly 

 through a bite. 



Foot-and-mouth disease is transmitted from cattle not only 

 to sheep, horses, pigs, cats, goats and dogs, but also to man, 

 frequently through the use of milk from an infected cow. 

 Siegel states that the exciting cause is a protozoon. 



A peculiar disease, hitherto only observed in parrots in 

 captivity, though occasionally transmitted to man, is that 

 known as psittacosis. The birds are attacked with diarrhoea, 

 become extremely weak and somnolent, and die after a short 

 time. Nocard found a special bacillus as the cause of this 

 disease. In the years 1892-97 there were seventy cases in 

 man recorded, and since then two others have occurred, namely, 

 those of the owner of a sick parrot, who died with symptoms 

 of a severe broncho-pneumonia, the bacillus of Nocard being 

 recognised by the serum test. His wife succumbed to a similar 

 attack. 



Finally, actinomycosis in cattle must be noted as an animal 



