1907.] on Certain Seasonal Diseases of the Sheep. 55?> 



stantial knowledge on matters of this kind is not to be acquired in a 

 day, but requires much patient observation over a long period before 

 anv relia1)le outcome can be obtained. It is my urgent plea, there- 

 fore, with all those concerned not to take these preHminary experi- 

 ments as samples of the ultimate success or failure of the treatment, 

 but rather as an index of what the best method of administration 

 may come to be. The subject, it must be remembered, is one which 

 is practically new to Science, and is one of the most involved in the 

 whole range of biology. In any such inquiry certain experiments 

 will succeed and others^will fail, and it ill becomes us to sit down and 

 weep over our failures. 



Preparation of Drench. — The method of preparing the drench is 

 as follows : The particular organism which is the cause of the 

 disease is isolated in a pure state from the abdominal, or peritoneal 

 liquid, as it is termed. This is afterwards grown artificiallv on a 

 liquid medium, and a certain quantity of the culture administered 

 to each animal. Whether a single administration is sufficient, or 

 whether the preventive is more effective when administered twice, 

 remains as yet only partially determined, but my experiments seem 

 to indicate that a single dosing is sufficient. 



In carrying out any treatment of this kind, one of the first points 

 is to discover what the animals in a particular district are suffering 

 from. Braxy is a common term, employed by those in the sheep 

 industry to indicate practically any disease from which sheep die in 

 the autumn and winter months, and although there is less liability to 

 error in the case of Louping-ill, yet there is again the same ten- 

 dency to include all those diseases which occur during the spring 

 months under this designation. It is obvious, therefore, that, unless 

 opportunity has been afforded of ascertaining, with certainty, what 

 the mortality in a particular district is due to, we are working quite 

 in the dark in recommending a remedy. This has been forced in 

 upon me by the experience of the last few years, and accordingly, 

 before preparing the drench for any particular locality or farm, I 

 make it a custom, if possible, to procure some of the peritoneal 

 liquid from some of the animals which have died, in order to 

 make certain what the disease or diseases are with which we are 

 dealing. By the examination of the peritoneal liquid, an excellent 

 guide is afforded to the diagnosis, and in order to avoid any source of 

 error, I always endeavour to prepare the drench from animals which 

 have died on the particular farm where the experiment is to be 

 carried out. 



Eesults of Treatment. — Our results have, accordingly, gone on 

 improving, from year to year. The last experiment with Louping-ill 

 was made during the spring of 11)06. Over the worst districts in 

 Scotland, and under the most trying conditions, we administered the 

 drench to loiO first year's sheep,"or " hoggs," as they are termed, 

 and out of these we had not a single death from Louping-ill. 



