312 Sheep Pox. 



breaking down, or necrosis of the cornea, with which occa- 

 sionally an acute inflammation of the internal parts of the eyes 

 becomes associated, leading finally to atrophy of the bulbus. 

 Vesicles which develop on the sclerotic portion of the conjunc- 

 tiva may extend to the cornea, leaving a permanent cloudiness 

 behind. 



The catarrh of the air passages may sometimes extend to 

 the finest bronchi, when it causes intense difficulty in respiration, 

 and a catarrhal pneumonia may develop as a result. 



The pox eruptions are usually associated with gastro- 

 intestinal catarrh ; in severe cases it becomes more intense, and 

 the resulting complete inappetence combined with the profuse 

 diarrhea exhausts the strength of the affected animals. 



The eruptions on the lower extremities, on the coronary 

 band, and in the interdigital space, lead not infrequently to 

 purulent inflammation of the sensitive lamina, and of the neigh- 

 boring joints, as in these places septic infection readily occurs, 

 whereupon the horny capsules, drop off, and general pyemia 

 develops from pus absorption. 



Of other complications there should be mentioned, suppura- 

 tion of the lymph glands, metastatic abscesses in various inter- 

 nal organs and in the subcutaneous connective tissue, diphthe- 

 ritic inflammation of the mucous membranes, pneumonia and 

 pleurisy, necrosis of the tendons, etc. 



Course. The course of pox is always acute, and except for 

 some of the outbreaks (see p. 309), is in the majority of cases 

 typical unless the development is hindered by outside condi- 

 tions. The development of the vesicle occurs with few excep- 

 tions always in the same order, and the other manifestations 

 also follow a typical course. Accordingly the average duration 

 of the disease, from the beginning of the exanthema until, the 

 scabs fall off and to the new formation of the epithelium, is from 

 3 to 4 weeks. The course may however be influenced by external 

 conditions, as it is known that the disease runs a slower course 

 in dry winter weather than in summer, and cold rainy weather 

 has an unfavorable effect on its course. Further, the disease 

 develops more slowly in anemic, poorly nourished animals, 

 and if they survive at all the period of desquamation especially 

 requires a longer time. 



In severe cases, with very extensive pox eruptions, death 

 may ensue even in the early stages of the disease, possibly from 

 hemorrhage. Usually however unfavorable changes take place 

 during the suppuration period, although in exceptional cases 

 animals may die even if they are on the road to recovery, as a 

 result of exhaustion or some complication. 



The mortality varies greatly in different outbreaks. While 

 the loss sometimes amounts only to from 2 to 5%, in other cases, 

 especially when the coalescing and hemorrhagic forms are more 

 frequent, more than half of the affected animals die. 



