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Circular 338, U. S. Department of Agriculture 



are evidences of inflammatory conditions about the follicles and their 

 sebaceous glands. As many as 200 mites may occur in a single hair 

 follicle. 



Usually the depilatory form of demodectic mange, due to the 

 uncomplicated cases of mite infestation as deseribed above, becomes 

 complicated in time through the invasion of the weakened and dis- 

 eased skin by pus-forming bacteria, and sometimes these complica- 

 tions appear to be present from the onset of the disease. This con- 

 dition is the pustular stage of the disease (fig. 6) and in this stage 

 the previously hairless and reddened areas now show numerous pus- 

 tules. In and under the skin there are numerous al)scossos or pus 



Fig. 5. — Dog with demodectic mange, depilatory form 



pockets, local destruction of the true skin or dermis takes place, 

 and, according to some investigators, some mites now wander out 

 of the hair follicles and may even enter the subcutaneous tissues. 

 The numerous pustules rim together and the skin becomes thickened 

 and so seriously weakened from disease that it is highl}^ susceptible 

 to injury from rubbing or contact with various objects- The odor 

 is very unpleasant. There is little or no itching in this stage. The 

 absorption of toxic products from bacteria and diseased skin tissue 

 serves to poison the entire system; bacteria may enter the blood 

 stream, causing generalized infection ; the bodily' functions are de- 

 ranged; the animal becomes emaciated and weak, and unless the 

 disease is checked the dog dies in a very pitiable condition. 



The disease usually I'uns a very slow course, commonly for months,, 

 and sometimes up to two years or longer. In rare cases there is. 

 spontaneous cure. 



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