Anthrax. 349 



Occurrence of Anthrax. 



A\ hile anthrax attacks all herb-eating animals^ hordes, cattle, 

 sheep, goats, deer, camels, guinea-pigs, and mice are the most 

 susceptible. Frohner asserts that a single bacillus introduced into 

 the subcutaneous connective tissue suffices to kill guinea-pigs and 

 mice. Cats, hares, and rabbits come next in order of susceptibility. 

 Dogs, pigs, and foxes are not so susceptible, although many cases in 

 pigs supposed to hare been anthrax have been proven to be erysipelas 

 (Friedberger). One attack confers in some animals an immunity to a 

 certain extent. 



Anthrax may occur sporadically, i.e., only one or but few animals 

 will be attacked : enzootically, i.e., the disease attacks cattle or other 

 animals in large numbers at the same time and place. 



But most frequently it is sporadic ; to a great extent its occurrence 

 is dependent on certain conditions of soil, vegetation, humidity, and 

 temperature, preferring black, loose, warm earth ; mould, chalk, marl, 

 and clay ; soils containing much waste organic matter, such as river 

 flats, boggy, swampy, or brittle land : also stable manure, a well- 

 marked connection existing between the disease, and the amount of 

 moisture in the soil. It is favoured by changes in the moisture of the 

 soil, developing best on moist, swampy, boggy laud, having an 

 impermeable sub-soil, which has partly dried up after long summer 

 heat. Wald and other observers have noticed an increase in the 

 number of cases of anthrax as the moisture decreases in the soil. 

 This also applies to dry mould, which becomes specially suitable for 

 the development of bacilli when following heavy rainfall, thunder- 

 storms, or floods, great heat with decrease of moisture sets in. Thus 

 it is, that the development of bacilli being favoured by heat, anthrax 

 is more prevalent during late spring, summer, and early autumn 

 months, while as cold checks the growth of these germs, cases 

 occurring in stock during cold weather have been contracted 

 through the medium of food or water supply. 



In passing, it is well to note the temperatures which are favourable 

 to the development of the spores and bacilli, as also those which are 

 fatal. The most favourable temperature for development is 95*^ F., 

 but it is arrested at 113° F., and killed under a jn-olonged heat of 

 131° F., but they can withstand cold provided it is not beloAv 14" F., 

 for three days ; sunlight also impedes their development. 



Post Mortkjm Appearance de Carcase. 



The cai'case is much swollen, the limbs ])ro]ecting. From mouth 

 and nostrils, as also from the anus, there esca])es, in the case of the 

 mouth and nostrils especially, a considerable quantity of serous 

 effusion, resembling l)lood and water mixed, and wliisked rapidly into 

 froth, which, when the latter has subsided, evinces no disposition to 

 coagulate ; the skin round the anus and vulva often burst, or in the 

 case of bullocks the scrotum. 



On pressure of the carcase by the foot a peculiar crackling, 

 whirring noise is heard, and the odour from the carcase when the 



