232 THE HORSE IN HEALTH AND DISEASE 



The horse is commonly infested with one of two species of lice, 

 but rarely with both at the same time. The Hematopinus macro- 

 cephalus is characterized by a long, narrow head and large, oval 

 abdomen (Fig. 65). It measures slightly more than ^g- inch long, 

 and obtains its living by biting and sucking the blood from its 

 host. The Tricodectes pilosus has a head that is rounded in front 

 and is broader than it is long. This louse lives principally on the 

 epidermal scales. It is about half the size of the former. 



To eradicate lice with dispatch, the horse must be clipped and 

 then carefully singed. Thorough daily currying and rubbing 

 with a rag moistened with kerosene is a means of getting rid of great 

 numbers of adults and nits. A decoction of stavesacre seeds, made 

 by boiling 4 ounces of the powdered seeds in a gallon of water, is 

 recommended as a wash. 



BOTS 



Bots are the larva of the Gastrophilus equi or bot-fly (Figs. 

 66, 67) . The female is woolly and gray brown in color. It hovers 

 around the legs and neck, where it deposits eggs and cements them 



Fig. 66. — Gastrophilus equi or bot-fly. An adult female magnified about three 



diameters. 



with a special secretion to the hair. These flies are most active 

 in the hot summer months. After a time the eggs hatch and the 

 minute larva irritate the skin, causing the host to bite the infested 

 part. In this way they gain entrance to the mouth, and event- 

 ually to the stomach. Once here they attach themselves to the 

 mucous lining and rapidly develop into the full-grown bot. Most 



