Sarcoptic Acariasis in Solipeds. 16 1 



-with acaricide (mercuric chloride, chloride of lime), whitewash, clean har- 

 ness and smear with phenated or formaline ointment. Treat all objects that 

 have been in the stable or in use about the horse. Disinfection of public 

 •places. Declaration of seller or custodian. 



Essential Cause. Sarcoptes Scabei Varietas Equi. Body 

 ovoid, marked division of cephalo-thorax into four plates, dorsal 

 papillae very acute ; dorso-abdominal bristles strong, straight, 

 rigid ; two anterior pairs of legs have suckers, the two posterior, 

 terminal hairs ; curved booklets on the second segments of the 

 first pair of limbs. Mature male .26 to .28 mm., ovigerous fe- 

 male .45 to .47 mm. Females by far the most numerous. A 

 transverse chitinous ridge on the abdomen connects with the pos- 

 terior pair of limbs, and with a horseshoe-shaped crest around the 

 ■generative organs. 



Accessory Causes. Beside the parasite other conditions 

 favor the development of the affection. These are such as con- 

 tribute to the survival or diffusion of the parasite, or tend to ren- 

 der the system a more inviting field for its growth. Poor con- 

 dition is almost constantly present, but this is usually the ac- 

 <;ompaniment of overcrowding, filthy buildings and yards, 

 and skin vrith excess of dandruff. W^arm seasons and hot 

 stables favor encrease of the acari, while cold renders them tor- 

 pid and diminishes reproduction. Most injurious of all is the 

 mingling of diseased with healthy stock, or, the occupation 

 of the same places in succession. Contamination of rail- 

 road cars, steamboats, ferry boats, market pens, stables, 

 yards and fields with rubbing posts, trees, stones, etc., the 

 use of the same clothing, combs, brushes, rubbers, pole, 

 shafts or harness must all be looked upon as prolific sources of 

 infection. 



Susceptibility of Different Animals. The sarcoptes of 

 -man can be conveyed to the horse, on which it burrows and 

 produces temporary acariasis, but this usually recovers spontan- 

 eously in 14 to 50 days (Delafond and Bourguignon). The same 

 is true of the sarcoptes of the lion (Delafond and Bourguignon), 

 cat (Herwig), dog, fox (Gerlach), and goat (Wallraff). 



The sarcoptes of the horse can be conveyed to man, and 

 in the army hundreds of soldiers have at different times suffered 

 <Sick, Megnin, Fleming, Longchamps, Geraud, etc.), but it 

 II 



