314 Sheep Pox. 



In the prognosis, the possilnlity of complications and after 

 effects (lameness, chronic ailment) should be given due con- 

 sideration. 



Treatment. In the treatment of sheep pox, regulation of 

 hygienic conditions is the essential factor to be considered. The 

 animals should be given proper food and pure, fresh, uniformly 

 warm air, wherefore in favorable weather it is best to keep 

 the sheep out of doors. The early slaughter of the severely 

 atfected animals appears indicated, because through this pro- 

 cedure the danger of a subsequent septic infection of the ani- 

 mals Avitli a milder attack is diminished. 



During the stage of incubation in the beginning of the affec- 

 tion, immune serum of high potency (see p. 317) may give 

 good service. 



Pox Immunization (Ovinatio). As recovery from pox usu- 

 ally confers upon the animals an immunity for their entire 

 lives, the production of the disease in a mild form appears 

 advantageous in all cases in which it is feared that the sheep 

 will become severely aifected from natural infection (emer- 

 gency immunization). This danger exists especially when the 

 disease has already attacked some sheep in a flock, and if its 

 further spread is expected. The situation is similar when the 

 disease has appeared in nearby localities, and the local condi- 

 tions appear to be favorable for the transmission of the disease 

 to the healthy herds. Under such conditions it should be aimed 

 to assure as much as possible a mild course for the disease, and 

 at the same time to reduce its duration. The vaccination of the 

 herds exposed to the infection answers for both purposes. The 

 disease which develops subsequently usually takes a more favor- 

 able course than in the natural infection, provided that the 

 vaccination has been carried out properly and with good vac- 

 cine. If the entire flocks have been vaccinated the disease usu- 

 ally disappears within a few weeks. At the same time the 

 spread of the infection to non-vaccinated herds should be pre- 

 vented by quarantining all infected herds. 



Vaccination of lambs at times when the disease does not 

 exist (protective or preventive vaccination) is not indicated. 



This procedure is at the present time used extensively in countries 

 in which sheep pox is prevalent, and is in many places carried out 

 annually by the shepherds. It appears to have a very old origin, hut 

 has attained a wider extension in Europe since Bourgelat in 1765 and 

 shortly afterwards Venel and Teisier, Ilurtrel d'Arboval and others 

 subjected the method to scientific examination, and recommended it 

 as a suitable protective method. In the first half of the last century 

 farmers and shepherds applied the vaccination very generally, and 

 the necessary vaccine was prepared for this purpose in specially estab- 

 lished institutes. 



As a matter of fact the vaccination produces a lasting immunity 

 against subsequent natural infection. The vaccination is followed with 



