480 DISEASES OF THE HORSE. 
Parasite: Psoroptes equi (Dermatocoptes equi, Dermatodectes 
equi). Matapy: Psoroptic acariasis—Psoroptic mange is less com-: 
mon than sarcoptic mange in horses, and as the parasite (Pl. XX XIX, 
fig. 3) 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 similar symptoms to those produced by 
the Sarcoptes. The same treatment 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 sub- 
jected to moist warmth. Infested pastures will therefore prove dan- 
gerous to horses for that length of time, and, with rubbing posts, etce., 
sheuld not be used. 
Parasrre: Chorioptes equi (Symbiotes equi, Dermatophagus equi, 
Chorioptes spathiferus). Marapy: Foot mange——tThe acarus (PI. 
XXXIX, fig. 2) attacks the heels and lower parts of the legs, espe- 
cially fe 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 parasite, 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 galline, or chicken acari, Mauapy: Poul- 
try acariasis—This is a large-sized acarus, though usually miscalled 
“hen louse,” and the disease “poultry lousiness.” The mite (Pl. 
XX XIX, fig. 4) lives in droppings and in crevices of chicken houses, 
but temporarily passes on to the skin of man and of the horse and 
other quadrupeds, when occasion serves. It causes much irritation, 
with the eruption of papules or vesicles and the formation of sores 
and scabs. The examination 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 trouble, and the removal of this and a white- 
washing with quicklime, with or without chlorid of lime, will prevent 
future attacks. The skin may still require bland ointments or 
lotions, as for congestion. 
Parasite: Larva of a Trombidium, Leptus americanus, or harvest 
bug, misnamed jigger (chigoe). Marapy: Autumn mange.—This 
parasite is a brick-red acarus, visible to the naked eye on a dark 
ground, and living on green vegetation i in many localities. It attacks 
man, and the horse, ox, dog, etc. , burrowing under the skin and giving 
rise to small papules and intalerable irritation. This continues for 
