232 THB HORSB. 



In papular eruption first remove the cause, then apply the same gen- 

 eral remedies as for simple congestion. In the more inveterate cases 

 use a lotion of one-half ounce sulphide of potassium in two quarts 

 water, to which a little Castile soap has been added. Or use a wash 

 with one-half ounce oil of tar, two ounces Castile soap, and twenty ounces 

 water. 



ANIMAL PARASITES OF THE SKIN. 



Mange or Ascariasis. This affection is due to the irritation of 

 the skin, caused by the presence of a nearly microscopic acarus or mite. 

 The disease varies, however, according to the species of acarus which 

 infests the skin, so that we must treat of several different kinds of 

 acariasis. 



The parasite is sarcopTES Equi. The disease is called SArcopTic 

 ASCARIASIS. This is the special sarcoptes of the horse, but under 

 favorable conditions it can be transmitted to ass and mule, and even to 

 man, and may live indefinitely on the human skin. The mite is nearly 

 microscopical, but may be detected with a magnifying lens among mov- 

 ing scurf taken from the infected skin. I^ike all sarcoptes, it burrows 

 little galleries in and beneath the scurf skin, where it hides and lays its 

 eggs and where its young is hatched. It is therefore often difficult to 

 find the parasite on the surface, unless the skin has been heated by a 

 temporary exposure to the sun or in a warm room. Even then it may 

 be needful to tie the .scab on the human arm till a prickling is felt, when 

 the acrus will be found in the center of a minute capule by its bite. Like 

 other acari this is wonderfully prolific, a new generation of fifteen indi- 

 viduals beingpossible every fifteen days, so that in three months the off- 

 spring of a single pair may produce a generation of one million five hund- 

 red thousand. The sarcoptes have less vitality than the non-burrowing 

 acari, as they die in an hour when kept in dry air apart from the skin at 

 a heat of 145" F. They live twelve to fourteen days apart from the 

 skin in the damp air of a stable. On a piece of damp hide they lived till 

 the twenty-fourth day, but were dead on the twentj^-eighth. 



The symptoms are an incessant, intolerable, and increasing itching of 

 some part of the skin (head, mane, tail, back, etc.), the horse inclining 

 himself toward the hand that scratches him, and moving his lips as if 

 himself scratching. The hairs may be broken and rubbed of, but the 

 part is never entirely bald as in ring-worm, and there may be papules or 



