236 GENERAL THERAPEUTICS FOR VETERINARIANS 



I. Protective Vaccination 



Varieties. — Depending upon how lopg before the outbreak of 

 an infectious disease the vaccination is made, three varieties of 

 protective vaccination are recognized: protective vaccination in 

 the restricted sense, prophylactic vaccination, and emergency 

 vaccination. 



Protective Vaccination in the Restricted Sense. — ^This is the 

 vaccination of all animals in healthy regions and stables, at a 

 time when the disease is not present, for the purpose of immunizing 

 them against a possible subsequent outbreak of the disease. A 

 good example of this variety of protective vaccination is the vacci- 

 nation of man against smallpox. In veterinary practice, protec- 

 tive vaccination against sheep pox (ovination) was formerly 

 employed; i.e., all of the sheep in a district were vaccinated al- 

 though there was no outbreak of the disease. On accoimt of the 

 great danger of introducing, spreading and to a certain extent of 

 artificially breeding the infection when vaccination is applied 

 under these circumstances, this variety of protective vaccination 

 has been abandoned. 



Prophylactic Vaccination. — ^This is also called precautionary 

 vaccination (preventive vaccination) and is used in disease-free 

 stables when the animals are threatened by an infectious disease 

 which has broken out in the neighborhood and which may soon 

 attack them. Prophylactic vaccination is especially important 

 for those regions in which on account of local or agricultural condi- 

 tions an infection is stationary (anthrax, black leg, lung plague, 

 swine erysipelas, swine plague, rinderpest, sheep pox) and where 

 because of the conditions an effective protection is not to be 

 expected from the operation of veterinary police measures. 



Emergency Vaccination. — ^This is the vaccination of animals 

 which are yet healthy but which are in an infected stable (premises, 

 herd), and is employed most frequently in connection with foot- 

 and-mouth disease. It is indicated: (1) when the infection of 

 the healthy animals can not be prevented; (2) when it is assured 

 that the artificially inoculated animals will acquire a mild form of 



