688 EXPERIMENT STATION RECORD. [Vol.38 



Enzootic paraplegia in sheep, I\I. E. Tabusso {Clin. Vet. [Milan], Rass. Pol. 

 Banit. e Ig., 40 {IDH), No. 16, pp. Jf57-Ji72, fig. 1; ahs. in Trop. Vet. Bui., 5 

 (1917), No. If, pp. 269-273). — This is a report of studies of the disease of 

 lambs occurring in the Peruvian Andes referred to as renguera by Gaiger in his 

 report of investigations noted above, and also known as pataleta, tembladera, 

 vertigo, and chucho. 



Experimental studies in hog cholera, R. A. Craig and R. A. Whiting 

 (Indiana Sta. Bui. 204 (1917), pp. 3-12, fig. 1). — This is a report upon micro- 

 scopical and cultural examinations made of blood and other virulent material 

 from cholera hogs and inoculation and blood attenuation experiments. 



The studies have shown that while Bacillus suipestifer, B. suisepticus, B. coli, 

 and diplococci may be present in the blood and tissues of cholera hogs those 

 present may not be the same in different outbrealis of the disease. B. suipesti- 

 fer is usually met with and B. coli is not uncommonly present in highly virulent 

 strains of blood. 



In order to prevent blood used for virus from losing its virulence and avoid 

 losses from septicemia in the hyperimmunes, it has been found necessary to 

 inoculate pigs a few weeks old with filtered hog cholera blood and use their 

 blood for inoculating the hogs used for producing virus. Since there is danger 

 of stock virus losing its virulence if every generation is filtered, the authors' 

 practice is to filter every second generation of blood used for inoculating young 

 pigs. 



In filtration and blood examination work more than 500 bacteria-free filtrates, 

 mostly blood and virulent salt solution from cholera hogs, were studied, five 

 different filters being used. It was found by inoculation tests that the filtrable 

 virus did not uniformly pass through Pasteur-Chambeiiand filter B. It was 

 noted that where filtration took place very slowly, extending over a period of 

 several hours, and a vacuum maintained, the bacteria would pass through the 

 different filters used. 



An experiment undertaken for tlie purpose of determining the character of 

 the hog cholera lesions produced by the filtrable virus is briefly reported upon. 

 Hog cholera blood and blood filtrate inoculation experiments in which pigs from 

 nonimmune mothers and weighing from 40 to 60 lbs. were inoculated with hog 

 cholera blood and blood filtrates from virus hogs from 4 to 8 days following 

 inoculation are reported upon in tabular form. The controls showed infection 

 in from 4 to 10 days after one or more of the inoculated pigs developed a tem- 

 perature of 104° F. The pigs inoculated with the 7- and S-day virus did not 

 live so long as those receiving 4-, 5-, and 6-day virus. It appears that 8-day 

 virus is no more virulent than 4-day and less virulent than 6-day virus. 



In determining the effect of heat hog cholera blood was heated in a water 

 bath for different periods, ranging from 30 minutes to 2 hours, and at different 

 temperatures. One lot of virus heated to 57° C. and three lots heated to from 

 51 to 55° for 2 hours produced the acute form of hog cholera in pigs that were 

 inoculated with them. Virulent salt solution heated to from 55 to 60° in a 

 water bath for 1 hour produced hog cholera in pigs inoculated with it. 



Hog cholera blood to which normal salt solution had been added in the 

 proportion of 1 : 2 was incubated for from 21 to 72 hours at 36.5° and afterward 

 heated 1 hour in a water bath at 60°, after which a 0.5 per cent phenol solution 

 was added. Several lots of pigs were inoculated with 2 cc. each, and with some 

 repeated in 5 days, but none reacted and all contracted hog cholera when 

 exposed 2 to 3 weeks later. 



Different proportions of hog cholera blood and antihog cholera serum were 

 mixed and kept in a refrigerator for one day, then heated to 60° in a water 

 Dath for 1 hour, and 0.5 per cent phenol added. Tests upon pigs showed the 



