478 DISEASES OF THE HOKSE. 



tincture of iodin twice a day for two weeks. Germs about the stable 

 may be covered up or destroyed by a whitewash of freshly burned 

 quicklime, the harness, brushes, etc., may be washed with caustic 

 soda, and then smeared with a solution of corrosive sublimate one- 

 half dram and water 1 pint. The clothing may be boiled and dried. 



Parasite: Achorion schonleini. Malady: Favus, or honeycomb 

 ringworm. — Megnin and Goyau, who describe this in the horse, say 

 that it loses its characteristic honeycomb or cup-shaped appearance, 

 and forms only a series of closely aggregated, dry, yellowish crusts 

 the size of hemp seed on the trunk, shoulders, flanks, or thighs. 

 They are accompanied by severe itching, especially at night. The 

 cryptogam, formed of spherical cells with a few filaments only, 

 grows in the hair follicles and on the cuticle, and thus a crust often 

 forms around the root of a hair. Like the other cryptogams, their 

 color, as seen under the microscope, is unaffected by acetic acid, 

 alcohol, ether, or oil of turpentine, while the cells are turned bluish 

 by iodin. For treatment, remove the hair and apply tincture of 

 iodin or corrosive sublimate lotion, as advised under the last para- 

 graph. 



Parasite : Microsporon furfur. Malady : Parasitic pityriasis. — 

 This attacks the horse's head where the harness presses, and leads to 

 dropping of the hair, leaving bald patches covered with a branlike 

 scurf, without any eruption, heat, tenderness, swelling, or rigidity of 

 the skin. A lotion of carbolic acid 1 dram and water 2^ ounces is 

 usually applied to effect a cure. 



ANIMAL PARASITES OF THE SKIN.^ 

 acariasis, or mange. 



This affection is due to the irritation of the skin caused by the 

 presence of nearly microscopic acari, or mites. 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. 



Parasite: S ar copies scahiei equi. Malady: Sarcoptic acariasis. — 

 This is the special Sar copies of the horse, but under favorable condi- 

 tions it can be transmitted to ass and mule, and even to man, and may 

 live indefinitely on the human skin. The mite (PI. XXXIX, fig. 1) 

 is nearly microscopical, but may be detected with a magnifying lens 

 among moving scurf talcen from the infected skin. Like all 8ar- 

 Goptes, it burrows little galleries in and beneath the scurf skin, where 

 it hides and lays its eggs and where its young are 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. The mite may be detected more readily by placing 



1 Revised by M. C. Hall. 



