SHEEP. 341 



the forming of the scabs the wool will generally begin to come off in patches, and, if 

 uncured, the animal will lose appetite and pine away and die. The period of incubation or 

 hatching of the eggs of this parasite varies according to surrounding circumstances, it greatly 

 depending upon the temperature and moisture to which they are subjected. Various experi 

 ments have been tried to ascertain the length of time required for this purpose, as well as 

 the time that they will retain their vitality and finally hatch under favoring circumstances; 

 but it has not yet been fully demonstrated. An authentic writer says respecting this subject: 



&quot; How long such eggs may be preserved without losing their vitality, is a question of 

 supreme importance to the live stock interests, inasmuch as the dangers from infested 

 buildings, clothing, harness, combs, brushes, rubbing posts, and lairs can only be limited by 

 the period of viability of the eggs. Unfortunately this limit has not yet been definitely 

 ascertained, though the analogy with the eggs of worms, and even of the higher animals, 

 would suggest that vitality be retained for months in favorable circumstances. Hence, in a 

 sheep-run full of bushes, stumps, and stones that have been used as rubbing-posts by the 

 scabby flock, the only safety consists in a prolonged absence of the ovine race, and the grazing 

 of such pastures by other animals on which the parasite which has infested this flock is incapa 

 ble of surviving.&quot; 



If the skin is examined in the early stages of the disease, it will be found to be covered 

 with yellowish pimples and scurf, after which the scabs form around the roots of the wool 

 and thicken until they finally raise the wool and draw its roots out of the skin. This is why, 

 as the disease advances, bare patches occur on the skin, and the wool hangs in shreds. 



In this disease, as well as most others, prevention is easier than the cure, and if animals 

 are well cared for, having a sufficient supply of good hay, roots, and grain in winter, together 

 with an easy access to pure water and salt, with good ventilation, warm, dry beds at night, 

 and are not overcrowded, they will not be liable to contract it in that season; while sweet 

 and abundant pasturage and other favoring conditions will not be liable to engender it in 

 summer. Exposure to the hot sun, as well as exertion to cause perspiration, has a tendency 

 to favor the activity and development of this pest; therefore a sheep pasture should always 

 be supplied with shade to which the sheep can resort when they choose. Healthy, well-fed 

 sheep are less liable to contract the disease than those weak and thin in flesh. 



In the first place all the diseased sheep should be separated from the well ones. Before 

 the disease has arrived at the stage where thick scabs have formed, the difficulty can be 

 reached by applying anything that will kill the minute insect that causes the trouble; hence 

 anything that will do this without injury to the sheep will cure the disease. Various reme 

 dies are used, but the most common one is the application of a strong decoction of tobacco. 

 From five to six pounds of tobacco, or tobacco stumps, steeped in as many gallons of water 

 until the strength is extracted, and then add enough water to make a bath of from twenty to 

 twenty-five gallons, will usually accomplish the result. 



It may be well to repeat this practice in a week or ten days to ensure a thorough cure, 

 and that those insects which may have escaped the first application may receive the .second, 

 as tobacco will kill any insect with which it comes in contact. Some wool growers add a 

 pound of blue vitrol to the above to every pound of tobacco ; three pounds of either soft or 

 hard soap, and a half pound of flowers of sulphur are also used with the mentioned quantity 

 of tobacco. 



When the scabs have become so formed on the surface that they require softening or 

 breaking up in order to reach the little parasites beneath, and which often furnish them a 

 secure shelter from external applications, a dressing of lard well rubbed into the skin is 

 sometimes used, followed with a good wash with strong soap suds, after which the dressing 

 may be applied for the destruction of the insects. It often becomes necessary to shear off 

 some of the wool in order to make thorough work in exterminating them. The sheep should 

 VOL. II. 20 



