310 VETERINARY HYGIENE 



ground. A similar organism has been isolated from the mouth 

 and air passages of healthy pigs, and it appears that it may reside 

 there as a harmless inhabitant until the vitality is lowered by the 

 swine fever virus. 



SWINE ERYSIPELAS. 



Swine erysipelas is a specific disease of pigs associated in the 

 acute form with a peculiar discoloration of the skin and due to a 

 bacillus, the bacillus of sivine erysipelas (LofHer, 1882). The dis- 

 ease was for a long time in this country confounded with swine 

 fever, but M'Fadyean* in 1891 first drew the distinction and 

 described three cases which had occurred in remote parts of 

 England. For some time previous to this the disease had been 

 recognised on the Continent as a morbid entity. 



The other domesticated animals are not susceptible to natural 

 infection, but instances have occurred in which man has become 

 inoculated through skin abrasions. Infection is most probably 

 telluric in origin and the organism leads a saprophytic existence 

 in the soil. Its saprophytic life explains quite well the marked 

 seasonal incidence of the disease, the majority of acute cases occur- 

 ring in the summer when presumably multiplication of the organism 

 in the soil is most rapid. Cases are, however, occasionally met with 

 in the autumn and spring, but in these cardiac valvular lesions are 

 generally present following an acute attack. Some observers con- 

 sider that the bacillus of swine erysipelas is frequently present in 

 healthy pigs, and the organism has been isolated from the tonsils 

 and ileo-csecal valves of such. These bacilli in healthy pigs have 

 been considered to have originated outbreaks, and the facts just 

 noted may explain the occasional occurrence of the disease among 

 pigs kept under exceptionally good hygienic conditions. 



On the Continent swine erysipelas appears as a rule as an acute 

 and very infectious malady, producing large outbreaks with 

 usually a high mortality. In this country, however, such outbreaks 

 have only rarely been met with, not more than a few cases as a 

 rule appearing in any one set of premises and the disease showing 

 no marked tendency to spread. Thus in 1914 the average number 

 of pigs in each herd attacked was only 12, and of these only 14-3 

 per cent, became affected. In 2057 of the 2892 outbreaks which 

 occurred in 1914 only one pig was attacked. Furthermore, experi- 

 ments made by a Departmental Committee appointed in 1895 

 showed that it is difficult to transmit the disease by feeding pigs 

 * Journ. Comp. Path., 1891, Vol. IV., p. 316. 



