Catarrhal Fever of Sheep — Blue-tongue or Bekzibkte. 519 



cases the membrane being- swollen, of a purple colour, with small 

 ulcers or erosions near the exit. 



The small intestines may also be found inflamed, more especially 

 when the disease is complicated by diarrhcea, in which case 

 the large intestines are found more or less affected. The spleen is 

 enlarged and the pulpa slightly softened. 



The liver is usually congested and the gall bladder full of dark 

 green bile. 



The kidneys are also congested and (jedematous, the covering 

 membrane being easily stripped off. The lungs are usually normal, 

 except in cases where there is redema and frothy mucus found in the 

 trachea and bronchial tubes. The blood is unaltered in appearance 

 and well coagulated. A little yellow fluid is found in the pericardial 

 sac, and there is also to be found petechia (blood markings) on the 

 endocardium of the left ventricle of the heart. 



C'URATIVE Tl?EATMENT. 



Many remedies have been tried and recommended, but many 

 recover as well without medicinal treatment, for it is found inadvis- 

 able to disturb or distress the sick sheep by continual dosing. 



The mouth lesions may be washed with some weak antiseptic 

 and astringent solution, such as alum or chlorate of potash, one tea- 

 spoonful to a bottleful of water, or a few grains of permanganate of 

 pttash to a pint of rain water. One dose of a mixture containing one 

 teaspoonful of a carbolic sheep dip, such as Little's dip, and one wine- 

 gjf.ssful of raw linseed oil is recommended. 



The patient should be placed under cover or in a cool shaded 

 place and disturbed as little as possible. If there are no sheds, the 

 sick sheep should be picked out of the flock as soon as they are noticed 

 sick, and placed in paddocks or sheltered spots near the homestead, 

 where they will not be disturbed. Allow them a free access to a lick 

 of eommon salt, which they appear to like and take readily. 



Susceptibility. 



This varies greatly. The pure Merino is most susceptible, 

 especially when young. Africander and Persian sheep seem to have 

 a considerable degree of immunity. Both old and young are liable 

 to attack, but it is found that sheep one to two years old contract the 

 disease most severely. It is noticed that unweaned young lambs 

 escape. The blood and also the serum of the blood of an affected 

 sheep is virulent during the whole course of the fever, and for a 

 considerable number of days after recovery. Blood obtained from a 

 severe case fifty days after the fall of fever on intravenous injection, 

 produced a typical sickness (SpreuU). 



Preventive Inoculation. 



The only method of preventive inoculation, for which a vaccine 

 is prepared, is Theiler's method. This vaccine is prepared by passing 

 Ihe virus through several generations of sheep and using the blood of 

 such animals. It is, in fact, an attenuated virulent blood j)reserved 

 by the addition of carbolic acid and glycerine. The inoculation sets 

 up a fever, which lasts for about a fortnight, producing mild 

 symptoms of the disease and some loss of condition. The mortality 



