SMALL POX ' 6G1 



with water, and stalls should be disinfected after occupation. If possible, 

 stables should be artificially heated and a comfortable temperature 

 maintained. Halters and fastenings should be so arranged that the 

 animals can not lick the scarified surfaces. Careful veterinary control 

 before vaccination and during the period of treatment must be observed 

 in order to eliminate animals with systemic disease or other complica- 

 tions. 



The calves may be vaccinated with material taken from previously 

 vaccinated animals. They may, on the other hand, be inoculated with 

 "seed virus" obtained from the vesicles of human vaccinia. This 

 method of using humanized virus for the inoculation of calves for 

 vaccine production is preferred by many workers and is spoken of 

 as " retrovaccination." 



Actual vaccination of the animals is done as follows : Calves which 

 have been kept under observation for at least a week are thoroughly 

 washed and cleaned and the abdomen is clipped and shaved over an area 

 extending from the ensiform cartilage to the pubic region, including 

 the entire width of the belly and the inner folds of the thighs. It is 

 best to shave the animal a day of two before vaccination so as to avoid 

 fresh scratches and excoriations. Just before actual operation the 

 animal is strapped to a specially constructed operating table in such a 

 way as to allow free access to the shaved area. This area is now thor- 

 oughly washed with soap and water followed by alcohol, or, in some 

 institutes, by a weak solution of lysol. If the latter is used, the field 

 of operation must again be thoroughly rinsed with sterile water. About 

 a hundred small scarifications are made in this area, preferably by 

 crossed scratches, covering for each scarification an area of about 3—1 

 square centimeters. Into these areas the virus is rubbed, using for each 

 small area a quantity about sufficient to vaccinate three children. Two 

 to three centimeter spaces are left between the lesions. The lesions are 

 then allowed to dry and may be covered with sterile gauze or, as in 

 Vienna,' with a paste made up of beeswax, gum arable, zinc oxid, 

 water, and glycerin. In some institutes the lesions are left entirely 

 uncovered. 



Ordinarily within about twenty-four hours after vaccination a narrow 

 pink areola appears about the scratches. Within forty-eight hours the 

 scratches themselves become slightly raised and papular, and within four 

 or six days typical vaccinia vesicles have usually developed. 



' Paul, loc. cit. 



