472 



DISEASES OF THE SKIN 



slight degree, and not in any sense at all like the intense itchiness of 

 sarcoptic mange; generally the animals when scratched or rubbed in the 

 affected region evince pain and endeavor to get away. In case the animal 

 should show a certain amount of itchiness it is not at all impossible that 

 the animal may have sarcoptic mange as well as dermodectic even if 

 all the symptoms of follicular disease are present. The pustular form 

 of the disease seems to attack the head and neck more frequently than any 

 other part of the body; that is, it commences there, as a rule, and grad- 



Fig. 171. — Head of dog affected with demodectes foUiculorum. 



ually spreads from that point to other parts of the body. The disease 

 goes through the phenomena of developing the nodules, accompanied by 

 acute local inflammation of the skin. This is followed by purulent 

 inflammation of the nodules and the discharge of a serous purulent or 

 sanguineous fluid. The abscess gradually dries up and the skin as a 

 consequence of the local thickening of the cuticle becomes traversed by 

 grooves and fissures and is covered with crusts and scales, assuming a 

 gray-blue color in some places and copper-red in others (see Plate), and 

 looks like elephant hide. As the nodules dry, there is apt to be a 

 secondary eczema, causing the animal to scratch more or less. 



