SCABIES. 785 



most frequently seen, and in greatest severity, during the cold 

 season of the year; not that the creatures upon Avhicli it 

 depends depart in the interval, but that they, from some 

 rather ill-understood conditions, seem in greater numbers and 

 activity during cold weather. 



The symptoms indicating the existence of this condition 

 are, in the early stages, not very attractive ; the fetlocks may 

 be somewhat thickened, and an extra amount of scurf may be 

 found over the skm, with a moderate amount of itching, 

 shown by rubbing one leg upon another, by gnawing the parts 

 with the teeth, or by vigorously and repeatedly stamping upon 

 the ground. Commonly the hind limbs are more liable to be 

 invaded by the mites than the anterior extremities. In severe 

 cases, the hair is removed in patches, and a heavy furfuraceous 

 crust exposed which rapidly undergoes change and removal. 



In all these manifestations of mange when existing for a 

 lengthened period, we find that considerable changes take place 

 in the tissues of the skin, visibly altering its appearance and 

 the manifestations of symptoms. 



Although attention to the form, intensity, and mode of pro- 

 pagation of these symptoms may often be sufficient to give us 

 well-grounded confidence regarding the nature of the malady, 

 none save the detection and identification of the mange mite 

 are to be regarded as certainly diagnostic. 



Means of Propagation. — Seeing that the contagion in every 

 case of scabies is either mature acari or their eggs, we can 

 understand that any means which will convey these from 

 diseased to healthy animals are sufficient for the propagation 

 of the diseased condition. This can be accomplished directly 

 by the contact of the suffering with the healthy, also indhectly 

 by the contact of the healthy through use of harness, clothing, 

 or stable-fittings and utensils which have previously been used 

 by the diseased. 



As all the forms are not alike contagious, we will find that 

 more liberties may be taken with the symbiotic and dermato- 

 dectic than with the sarcoptic variety. 



This last, it may be noticed, is also alone capable — by the 

 transmission of the acari — of propagation and a variable tenure 

 of life on the skin of man and other animals. 



The retention of vitality by the acari, on their removal from 



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