CLINICAL EVIDENCE OF VALUE OF SERUM 445 



kind the rule should be to give a large dose of serum in those ani- 

 mals that are already sick, as shown by loss of appetite, staggering 

 gait, muscular weakness, and desire to remain in their nests, and 

 also in those animals that do not show these symptoms, but do 

 show a rise in temperature above 105° F. In the animals that are 

 still free from the disease at the time of treatment and do not show 

 any rise in temperature the better plan is to give the double method 

 of treatment. 



In following this rule we are certain of having at the end of the 

 outbreak a herd remaining every one of which has developed the 

 power of making in its own bodies the germ-fighting agents which 

 will protect it from disease during the remainder of its natural life- 

 time. 



This outbreak also serves to show very nicely the difference in 

 course of an outbreak of chronic cholera from that of the acute type. 

 In the chronic form of the disease the course is more long drawn out, 

 and probably not more than 50 per cent, of the animals will die. 

 A large percentage, however, of those which survive the attack are 

 left in a stunted condition and are never of any account afterward. 

 These runts are usually better knocked in the head, as they will 

 never pay for the grain they eat. 



Herd Number Eleven. — The herd which formed the basis for 

 the eleventh of this series of experiments was located in the north- 

 east quarter of Section 36, Grant Township. This is in the im- 

 mediate vicinity of Shipley, Iowa, and was the center of an infected 

 neighborhood at this time. The herd was first seen on October 

 15th, and on that date was apparently unaffected, although hog- 

 cholera was present on other farms not over half a mile distant. 

 In carrying out the experiment, arrangements were made with the 

 owner to administer the simultaneous method of treatment, and 

 later on to expose one-half of the animals to hog-cholera on an 

 infected farm in the neighborhood. 



There were 36 animals in this herd, and the treatment was ad- 

 ministered to 35 of them. One animal got away during the time 

 the treatment was being given, and on this account was left un- 

 treated. The 35 animals injected were shoats, averaging from 30 

 to 75 pounds, and each hog received 20 c.c. of serum and with this 

 2 c.c. of virus blood. 



