306 ANTHRAX 



sterile silk threads are dipped, which, after being dried over 

 strong sulphuric acid in a desiccator, can be kept for long 

 periods of time in an unchanged condition. For use they are 

 placed in the germicidal solution for the desired time, then 

 washed with water to remove the last traces of the reagent and 

 laid on the surface of agar or placed in bouillon, in order that if 

 death has not occurred growth may be observed (see Chap. IV.). 



Anthrax in Animals. Anthrax occurs from time to time 

 epidemically in sheep, cattle, and, more rarely, in horses and 

 deer. These epidemics are found in various parts of the world, 

 although they are naturally most far-reaching where legal pre- 

 cautions to prevent the spread of infection are non-existent. 

 All the countries of Europe are from time to time visited by the 

 disease, but in some it is much more common than in others. 

 In Britain the death-rate is small, but in France the annual 

 mortality among sheep was probably 10 per cent of the total 

 number in the country, and among cattle 5 per cent. These 

 figures, however, have been largely modified by the system of 

 preventive treatment which will be presently described. In sheep 

 and cattle the disease is specially virulent. An animal may 

 suddenly drop down, with symptoms of collapse, quickening of 

 pulse and respiration, and dyspnoea, and death may occur in 

 a few minutes. In less acute cases the animal is apparently out 

 of sorts, and does not feed ; its pulse and respiration are 

 quickened ; rigors occur, succeeded by high temperature ; there 

 is a sanguineous discharge from the bowels, and bloody mucus 

 may be observed about the inouth and nose. There may be 

 convulsive movements, there is progressive weakness, with cyanosis, 

 death occurring in from twelve to forty-eight hours. In the 

 more prolonged cases widespread oedema and extensive enlarge- 

 ment of lymphatic glands are marked features ; and in the glands, 

 especially about the neck, actual necrosis with ulceration may 

 occur, constituting the so-called anthrax carbuncles. Such 

 subacute conditions are especially found among horses, which 

 are by nature not so susceptible to the disease as cattle and 

 sheep. 



On post mortem examination of an ox dead of anthrax, the 

 most noticeable feature one which has given the name " splenic 

 fever " to the disease is the enlargement of the spleen, which 

 may be two or three times its natural size. It is of dark-red 

 colour, and on section the pulp is very soft and friable, sometimes 

 almost diffluent. A cover-glass preparation may be made from 

 the spleen and stained with watery methylene-blue. On examina- 

 tion it will be found to contain enormous numbers of bacilli 



