HOG CHOLERA : PREVENTION AND TREATMENT. 



23 



after exposed to cholera, they seem to acquire a permanent immunity, 

 but this is not always the case, and therefore serum alone can not 

 be depended upon to produce a lasting immunity even though the 

 treated pigs be promptly exposed to cholera. 



It has been stated that serum alone can be used to treat sick hogs. 

 This is true within certain limitations. Ordinarily it is efficacious 

 in the very early stage of the disease, but apparently has only slight 

 effect when the disease has advanced so that a hog shows visible 

 signs of sickness, such as weakness, lack of appetite, sluggishness, etc. 



DOSAGE OF SERUM ALONE. 



The quantity of serum required for producing immunity or for 

 curing infected animals is influenced by a number of conditions, 

 chief among these being the condition and susceptibility of the pigs 

 and the strength or potency of the serum which is used. No hard 

 and fast rule can be laid down, but as a sort of general guide the 

 doses in the following table are suggested: 



Table 4. — Dose? for serum-alone inoculation. 



Weight of hoc;. 



Dose of serum. 



Below 10 pounds 



10 to 15 pounds 



20 to 30 pounds 



40 to 75 pounds 



100 to 150 pounds 



175 pounds and over. 



10 cubic centimeters. 



15 cubic centimeters. 



20 to 25 cubic centimeters. 



30 cubic centimeters. 



40 to 60 cubic centimeters. 



80 cubic centimeters. 



If the herd is infected the dose of serum should be increased slightly for all appar- 

 ently well hogs, and all hogs showing high temperatures or other evidence of disease 

 should receive at least a dose and a half of serum. 



From what has been said, it will be seen that serum alone is to 

 be recommended particularly under the following conditions: 



1. For the treatment of hogs in the very early stages of the dis- 

 ease, as shown by the presence of fever rather than by visible 

 symptoms. 



2. For the treatment of hogs which need to be protected for only 

 a short time, as, for example, a herd which is to be sent to market 

 within 3 or 4 weeks. Or in the case of hogs which are to be shipped 

 by rail and thus perhaps exposed to infection for only a short time 

 while in transit. 



3. In the case of very young pigs, when the administration of the 

 simultaneous inoculation is objected to by the owner. In such a 

 case, however, the pigs should be removed immediately and kept 

 from exposure to infection, such as infected lots, or else within 3 or 4 

 weeks they should receive the simultaneous inoculation or a second 

 injection of serum alone. 



