368 VETERINARY HYGIENE 



is more likelihood of animals being imperfectly dipped than with 

 the larger swim bath. The hand bath is usually made of wood 

 or cement concrete and its common dimensions are 4 feet long, 

 4 feet deep, and about 1 foot 9 inches wide. With such a bath 

 the sheep are lifted in and turned over on their backs ; they should 

 be held in the bath for two minutes, or if less time is allowed 

 then the dip must be well rubbed into the fleece. The head must 

 be immersed at least twice, and it is important to see that the ears 

 are filled with the dip. A swim bath is so constructed that the sheep 

 are not handled but are driven down into the bath, through which 

 they must swim, the time occupied being two minutes. The head 

 must be immersed in the dip. Such a bath is easier on the men, 

 saves time and is better for the sheep, as they are less liable to be 

 hurt, and, furthermore, the dipping is more certain. The dimensions 

 of such a bath would be 30 feet long at the top and 20 feet at the 

 bottom, 5 feet deep and about 1 foot 9 inches wide. The sheep 

 walk down into the tank and having swum through walk up and 

 out. A bath having dimensions intermediate between the two 

 described is often used. Whatever type is used it is of fundamental 

 importance that the animals remain in long enough for the dip to 

 thoroughly permeate the fleece. Having gone through the bath 

 the sheep must be allowed to drip on a place so that the superfluous 

 dip runs back into the tank; such drippings must not be allowed 

 to run off on to pasture, as many dips are poisonous and fatal 

 poisoning may occur. When the dip becomes reduced in volume 

 it must be made up with dip of the requisite strength and not with 

 water. 



As well as being an efficient parasiticide a suitable dip must 

 possess other qualifications. The permeability or " soakability " 

 of the dip is of great importance, especially when the fleece is 

 greasy. It must not harm the sheep nor damage the fleece. Wool 

 staplers object to carbolic and pitch oil preparations. For dips 

 recommended by the Ministry of Agriculture see the Sheep-Scab 

 Order of 1920. 



Rene's dip is as follows : Dissolve arsenious acid, 2 Ibs., 

 sulphate of zinc, 10 Ibs. and aloes, 1 Ib. in 20 gallons of water. 



Rene recommends that the sheep be well scrubbed while in the 

 dip, and that they remain in it from one to five minutes. The sheep 

 should have been previously shorn and, before being dipped, should 

 be well soaped and all crusts on the skin thoroughly softened.* 



A. Seymour-Jones suggests that a " sulphur " dip might be made 

 by immersing the sheep in a bath of sodium hyposulphite of 5 to 

 * Progres Agricole, 1917, XXXI., p. 200, through Vet. Rev., I., p. 394. 



