450 DISEASES OF THE HORSE. 



among the domestic animals to horse, ox, goat, dog, cat, and in rare 

 instances to sheep and .swine. Hence it is common to find animals of 

 different species and their attendants suffering at once, the diseases 

 having been propagated from one to the other. 



Symptoms. — In the horse the symptoms are the formation of a cir- 

 cular scurfy patch where the fungus has established itself, the hairs of 

 the affected spot being erect, bristly, twisted, broken, or split up and 

 dropping off. Later the spot first affected has become entirely bald, 

 and a circular row of hairs around this are erect, bristly, broken, and 

 split. These in turn are shed and a new row outside passes through 

 the same process, so that the extension is made in more or less circular 

 outline. The central bald spot, covered with a grayish scurf and sur- 

 rounded by a circle of broken and split hairs, is characteristic. If the 

 scurf and diseased hairs are treated with caustic potash solution and 

 put under the microscope the natural cells of the cuticle and hair will 

 be seen to have become transparent, while the groups of spherical cells 

 and branching filaments of the fungus stand out prominently in the 

 substance of both, dark and unchanged. The eruption usually appears 

 on the back, loins, croup, chest, and head. It tends to spontaneous 

 recovery in a month or two, leaving for a time a dappled coat from 

 the spots of short, light-colored hair of the new growth. 



The most effective way of reaching the parasite in the hair follicles 

 is to extract the hairs individually, but in the horse the mere shaving 

 of the affected part is usually enough. It may then be painted with 

 tincture of iodine 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 

 ringtoorm. — 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 

 ciyptogam, 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 ciyptogams, 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 iodine. For treatment, remove the hair and apply tincture of 

 iodine 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 



