DISEASES OF THE SKIN. 139 



^RTfRITVS. 



Prurigo andPrurltus are not to te confounded as being expressive of the 

 same condition. The former is a disease always associated with papular 

 development, whUe the latter is intense itching, purely a nervous mani- 

 festation, unattended with any visible changes in the skin or tissues. 



Pruritus is a special form of skin irritation connected with many physi- 

 ological changes. Thus, in diseases of the Mdneys, jaundice, and other 

 liver disorders, plethora due to over feeding and want of exercise, piles, 

 worms, constipation, indigestion, and a sluggish cutaneous circulation 

 from lack of cleanliness and proper grooming, are influences whioh in- 

 duce pruritus. The affection is not uncommon in old dogs dependent upon 

 the invariable changes in the skin induced by age. 



In young dogs the disease is more eommton among those of a highly 

 nervous temperament, possibly the result of continued inbreeding. When 

 intense itching exists the animal must be very carefully examined to 

 determine if possible the cause. Pruritus must not be accepted as the 

 diagnosis until all doubt as to the existence of diseases of tlie skin and 

 parasites is removed. 



The condition of the animal will suggest what constitutional treatment 

 to employ. All disorders are to be overcome and the general health im- 

 proved by medicine, dieting, proper exercise, etc. 



Frequent bathing or immersions in cold water when the weather per- 

 mits, or the use of diluted vinegar or alcohol as lotions, are the local 

 treatments to employ. 



. Faws. 



This disease for which a variety of names is given, among them honey- 

 comb ringworm, is characterized by the formation of sulphur-yellow 

 crusts. These are generally rounded and present a peculiar appearance ; 

 in their earlier stages they resemble much the eruption in ringworm, 

 namely : thin, roundish scales pierced by a hair. These scales then form 

 in their centre a yellow prominence which rapidly increases in size 

 and at their bases the surface Is slightly hollow; thus nearly all present 

 an outer concave and an inner convex surface, what is called a crab's eye 

 appearance. 



Tlie crusts throw off a peculiar musty odor, and when removed a cup- 

 like depression is found in the skin, which may be ulcerated or have but 

 a thin scarf-skin covering it. 



In some instances the disease appears as minute vesicles, formed in 

 circles, which dry to yellow crusts (scutula) . 



