594 



THE DISEASES AND DISORDERS OF THE OX. 



root of the tail, and from these parts it extends over the body. 

 The hair of a mangy ox will come oflF here and there, and if the 

 dry scales which are present be removed, small raw pimples 

 discharging a yellowish serous fluid may be seen. 



In order to be absolutely certain that the disease from which 

 an ox is suflPering is really mange, a little scurf may be removed, 



Fig. 78. — Dermatodectes Bovis (Gerlach). 



and should then be very carefully examined under the micro- 

 scope, in which case the acari may be observed. The acari can 

 sometimes even be seen by the aid of strong sunlight with the 

 naked eye as minute white points moving about rapidly. In 

 chronic cases the skin becomes thick and thrown into folds, 

 especially in those parts, such as the neck, breast, and thighs, 

 where it hangs loosely. The disease is more common among 

 debilitated, and especially among badly kept, animals, than among 

 those which are well looked after and in good condition. It is to 



