452 DISEASES OF THE HOKSE. 



than once, and should always be repeated after fifteen days, to destroy 

 the new brood that may have been hatched in the interval. All har- 

 ness and stable utensils should be similarly treated; blankets and 

 rubbers may be boiled, and the stalls should be covered with a white- 

 wash of quicklime, containing one-fourth pound of chloride of lime 

 to the gallon. 



Parasite: Sarcoptes mutans. Malady: Sarcoptic acariasis of 

 fowls. — This parasite belongs to chickens, but can live on the skin of 

 the fox and horse as well. A troublesome mange may therefore at 

 times be traceable to the proximity of a chicken roost. The general 

 symptoms and treatment are essentially the same as for Sarcoptes 

 scdbiei equi. 



Pakasite: Psoroptes equi {DerTnatocoptes equi, Dermatodectes 

 equi). Malady: Psoroptio acariasis. — This produces the most fre- 

 quent mange in horses, and as the parasite only bites the surface and 

 lives among the crusts under the shelter of the hair, it is very easily 

 discovered. It reproduces itself with equal rapidity and causes simi- 

 lar symptoms to those produced by the Sarcoptes. The same treat- 

 ment will suffice and is more promptly effectual. The purifying of 

 the stable must be more thorough, as the Psoroptes will survive 

 twenty to thirty days in the moist atmosphere of a stable, and may 

 even revive after six or eight weeks when subjected to moist warmth. 

 Infested pastures will therefore prove dangerous to horses for that 

 length of time, and, with rubbing posts,-etc., should not be used. 



Parasite : ChoHoptes hovis {Symhiotes equi, Dermatophagus equi, 

 CJiorioptes spatMferus) . Malady: Foot mange. — ^This acarus at- 

 tacks the heels and lower parts of the legs, especially the hind ones, 

 and may be present for years without extending upon the body. 

 Like the Psoroptes, it lives on the surface, on the hairs, and among 

 the scabs. " It gives rise to great itching, stamping, rubbing of the 

 one leg with the other, and the formation of papules, wounds, ulcerous 

 sores, and scabs. The intense itching will always suggest this para- 

 site, and the discovery of the acarus will identify the disease. The 

 treatment is the same as for the Sarcoptes, but may be confined to the 

 legs and the parts with which they come in contact. 



Parasite : Dermanyssus gallincB, or chicken acari. Malady : Poul- 

 try acariasis. — This is a large-sized acarus, though usually miscalled 

 "hen louse," and the disease "poultry-lousiness." The mite lives in 

 "the hen manure and adjacent woodwork, but temporarily passes on 

 to the skin of man and of the horse and other quadrupeds, whexi 

 occasion serves. It causes much irritation, with the eruption of 

 papules or vesicles and the formation of sores and scabs. The ex- 

 amination of the skin is usually fruitless, as the attacks are mostly 

 made at night and the effects only may be seen during the day. 

 The proximity of hen manure swarming with the acari explains the 



