68 VACCINE AND SERUM THERAPY 



secondary lesions for which the B. hronchisepticus is 

 responsible. Dose of serum is 10 to 30 c.c, repeated 

 each twenty-four hours when used as treatment. 



Vaccination. — Vaccines have been prepared for active 

 immunisation against distemper. They consist gener- 

 ally of a mixed infection vaccine, prepared from strains 

 of the B. hronchisejHicus, streptococci, and Staphylo- 

 coccus albus and aureus. Dose 2 c.c, following an 

 initial injection of antiserum. As in the case of the 

 serum, this vaccine does not prevent the disease, and 

 as it is a stock vaccine, it cannot influence the course 

 of the disease very much owing to the different 

 degrees of virulence of the strepto- and staphylococci 

 group of organisms. In some cases where good 

 results follow from the use of stock vaccines in 

 diseases caused by these organisms, it may happen 

 that the organisms responsible for the disease chance 

 to be the same strain as those from which the 

 vaccine is prepared, hence the beneficial results 

 obtained from this particular vaccine. 



Up to the present, no sera or vaccines have been 

 prepared which can to any extent be relied upon to 

 protect an animal from distemper ; but by the use 

 of the serum a protection is given to the animal from 

 secondary infection by the B, hroncltiscpticiis, and in 

 some cases the vaccine has the same effect in protect- 

 ing the animal against the invasion of the strepto- and 

 staphylococci. Hence it is advisable to employ the 

 serum, or the serum and vaccine combined, where 

 young animals are exposed to distemper infection. 



