DISEASES OF THE SKIN. 481 



two o;r three days only from a single invasion, but will last until cold 

 weather sets in if there is a fresh invasion daily. Horses at pasture 

 suffer mainly on the lower part of the face. If kept indoors the 

 disease will disappear, or if left at pasture a weak tar water or solu- 

 tion of tobacco may be applied to the face. 



TICKS. 



The wood ticks are familiar to inhabitants of uncultivated lands, 

 and prove troublesome parasites to man and beast alike. The tick 

 lives on bushes, and attaches itself to the mammal only to secure 

 a feast of blood, for when gorged it drops, off to sleep off its debauch 

 on the soil. The tick produces great irritation by boring into the 

 skin with its armed proboscis. If pulled out, the head and thorax 

 are often left in the skin. They may be covered with oil to shut 

 out the air from their breathing pores, or by touching them with 

 a hot penknife they will be impelled to let go their hold. 



GRUBS IN SKIN. 



Parasite: Hypoderma lineaia. Malady: Larvw (gruhs) tinder 

 the skin.. — ^The larvae of a fly (probably Hypoderma Uneata, whose 

 larvae in the skin of cattle are commonly known as "warbles") are 

 occasionally found in little sacs beneath the skin of horses. The 

 mature larva escapes in early summer and develops into a fly. In 

 districts where they exist the grubs should be pressed out of the skin 

 in the course of the winter and destroyed. 



LARViE (GRUBS) ON THE SKIN, OR FLYBLOW. 



The following flies, among others, deposit their eggs on open sores 

 or on wet, filthy parts of the skin, where their larvae or grubs give 

 rise to serious trouble : Ludlia ccesar (bluebottle) , CochUomyia macel- 

 laria (screw worm fly), Musca vomitoria (meat fly), and Sarcophaga 

 camaria (flesh fly) . To prevent their attacks, wet, filthy hair should 

 be removed and wounds kept clean and rendered antiseptic by a 

 lotion of carbolic acid 1 part, water 50 parts, or by a mixture of 1 

 ounce oil of tar in 20 ounces sweet oil, or by some other antiseptic. 

 If the grubs are already present they should be picked off and one 

 of these dressings freely applied. 



FLIES. 



A number of flies attack horses and suck their blood, producing 

 great annoyance and in some instances death. These insects not only 

 suck the blood, but also often instill an acid poison into the skin, and 

 in exceptional cases transfer infectious germs from animal to animal 

 by inoculation. 



Various devices are resorted to to prevent the attacks, as to sponge 

 the skin with a decoction of walnut or elder leaves, of tobacco, to dust 

 36444°— 16 — --31 



