686 SCABIES — SCAB — MANGE. 



(2.) Shear all the sheep at one time, and immediately after shearing 

 confine them to one half the farm for two to four weeks. Many 

 persons prefer to dip immediately after shearing. 



(3.) At the end of this -time dip every sheep (and every goat also, 

 if there are any on the farm). 



(4.) Ten days later dip the entire flock a second time. 



(5.) After the second dipping, place the flock on the portion of 

 the farm from which they have been excluded during the previous 

 four or five weeks. 



(6.) Use the dip at a temperature of 100° to 110° Fahr. 



(7.) Keep each sheep in the dip for two minutes by the watch — 

 do not guess at the time — and duck its head at least once. 



(8.) Be careful in dipping rams, as they are more likely to be 

 overcome in the dip than are the ewes. 



(9.) Injury may, however, result to pregnant ewes, which must 

 on this account be carefully handled. Some farmers arrange a stage, 

 with sides, to hold the pregnant ewes, which is lowered carefully into 

 the vat, and raised after the proper time. 



(10.) In case a patent or proprietary dip, especially an arsenical 

 dip, is used, the directions given on the package should be carried out 

 to the letter. ''^' 



CHORIOPTIC MANGE, SYMBIOTIC MANGE, FOOT SCAB. 



This disease was studied in Germany by Ziirn in 1874, and by 

 Schleg in 1877. It has not yet been seen in France. 



Causation. The sole cause is the presence of Chov'wptes scahiei 

 (r. oris). Contagion is favoured by the animals being in poor con- 

 dition. The disease extends very slowly. Only 2 to 3 per cent, of the 

 animals are affected, and the sufferers are usually those with fine 

 skins. 



German shepherds consider this disease to be due to an excessive 

 allowance of salt, because it is most common during the winter, when 

 the sheep are housed. Needless to say, this theory is incorrect. 



Symptoms. Sometimes this form of mange attacks the limbs and 

 develops very slowly. It commences about the pasterns, and gradu- 

 ally extends upwards towards the knee or hock. It really advances 

 beyond these points. The parasites are much smaller than those of 

 common scab, and are often overlooked. The sheep stamp their feet 

 and scratch and bite the infected parts, sometimes transferring the 

 disease to the lips and face, where it may ])ersist for a time. 



In very old standing cases which have been entirely neglected, 

 it may be met with in the region of the armpit and thigh, the 



