858 VETEEINAEY HYGIENE 



taining a dry floor ; this can only be obtained by care in 

 selecting the site, draining by means of surface channels 

 any part that runs into it, so as to carry the water off, and 

 raising the ground of the pens above the surrounding level 

 with dry earth or burned clay, over which straw should be 

 laid. 



At times cow's milk has to be employed in the rearing of 

 lambs and may produce diarrhoea, but besides this there 

 is a very fatal form of diarrhcea among lambs two or three 

 days after birth known as ' white skit,' due, it is supposed, 

 to the disagreement of the ewe's milk. It is more than 

 likely it is due to the same cause as white scour in calves, 

 viz., an organism which enters the body by the mouth and 

 perhaps navel. In combating this disease the ordinary 

 method of moving the fold must be adopted, the destruction 

 of the evacuations carried out, isolation of the sick practised, 

 the greatest cleanliness insisted upon, and the group system 

 adopted (see p. 495). 



A green diarrhcea frequent at weaning time is considered 

 by some to be more fatal than the white variety. Green 

 diarrhoea is caused by sudden change of diet ; all changes 

 in food should only be gradually brought about. 



A very fatal form of aphtha occurs in lambs, probably 

 the result of maternal infection. The teats of the ewe 

 crack and ulcerate and so infect the lamb, which suffers in 

 the mouth, nostrils, and lips. It is still a doubtful point, 

 whether the dam infects the lamb, or the lamb infects the 

 ewe. This is probably a purely infectious disease, and 

 when many animals are affected it is a most difficult one 

 to legislate for ; the ewes suffer from distended udders, the 

 lambs from hunger owing to their inability to suck. 



Small flocks can be dealt with, the ewes' udders being 

 stripped, but where large numbers are affected it becomes 

 impossible to deal with them. Isolation of the affected is 

 of primary importance, grouping the cases into different 

 degrees of severity, frequent changes of fold, insuring that 

 hay racks and feeding troughs are put back in the pen they 

 belong to, are elementary principles which suggest them- 



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