MICROBIAL DISEASES OF MAN AND DOMESTIC ANIMALS 873 



may be differentially stained as in the Lentz method. Some careful 

 students of rabies regard the Negri bodies as protozoa and consider 

 them to be the infectious agent. Proof of this belief is still lacking 

 inasmuch as it has not yet been conclusively shown that they are 

 actually living organisms. 



A wound infected by a rabid animal should be thoroughly cauter- 

 ized, under anaesthesia If desired, at the earliest possible moment, and 

 this cauterization should not be omitted even if twenty-four hours have 

 elapsed. Cauterization cannot be relied upon to prevent the develop- 

 ment of rabies, but it does serve to prolong the incubation period. The 

 Pasteur treatment should then be instituted as soon as possible, and 

 it has proved to be practically an absolute preventive, provided the 

 incubation period of the disease is sufficiently prolonged for the treat- 

 ment to become effective, and this is usually the case. The treatment 

 consists in the daily subcutaneous injections of altered fixed virus for 

 a period of about three weeks, and is most effectively given at Pasteur 

 Institutes devoted especially to this work. Valuable animals as well 

 as man may be successfully treated in this way. 



The general prevention of rabies depends almost solely upon the 

 efficient control of all dogs in a community. General muzzling, strictly 

 enforced, is a certain preventive of rabies, and in countries where this is 

 done rabies is practically unknown. 



SWAMP FEVER* 



This is a comparatively new disease of horses so far as definite infor- 

 mation is concerned, but is in reality an old disease that has been 

 described under a variety of names for many years. It is known by 

 various names as infectious anaemia, malarial fever, horse typhoid, 

 "plains" paralysis, and pernicious anaemia, and has been recognized 

 in many portions of the United States and Canada. 



This disease is usually of chronic type, but acute cases have been 

 reported. There is usually a long illness extending from a month to a 

 year or more, and marked by periods of fever and debility, alternating 

 with periods of apparent recovery. The phase of apparent illness is 

 characterized by fever, general weakness, and staggering gait, and the 

 disease terminates fatally, as a rule. Some cases undoubtedly termi- 

 nate as " carriers." The peculiar features of the disease are the 



* Prepared by M. H. Reynolds. 



