1908]. 



Swine-Fever. 



337 



it will be seen that the death-rate from swine-fever varies in 

 different outbreaks. From inquiries conducted by the Board 

 during 1907 it would appear that, taking one outbreak with 

 another, the average death-rate is about 30 per cent. There- 

 is no other disease of swine in Great Britain which, as a 

 general rule, gives rise to continued unthriftiness, and none, 

 with the exception of swine erysipelas and pneumonia, is likely 

 to cause such a high mortality. The experience of the Board, 

 however, over a number of years shows that when outbreaks 

 of the two latter diseases are reported, the trouble not in- 

 frequently turns out to be swine-fever. 



To sum up shortly, pig owners may reasonably be expected 

 to report under the following circumstances : (1) When a 

 number of animals are dying ; (2) when a number of animals 

 are sick or unthrifty ; (3) when periodic deaths are taking 

 place, even if the other pigs appear healthy ; (4) when a high 

 mortality is noticed in sucking or newly weaned pigs, even if 

 the older ones appear to be healthy ; (5) when a number of 

 pigs are sick or dying with symptoms of pneumonia, diarrhoea, or 

 what may appear to be acute swine erysipelas. The fact of the 

 suspicious symptoms appearing first in pigs which have been 

 recently purchased, or in a sow which has been to the boar, in 

 pigs recently cut, or in those which have been off the premises 

 to a market, and have been brought back, should always 

 increase the suspicion, but careful inquiry into the circumstances 

 in connection with a considerable number of outbreaks shows- 

 that the fact of no new pigs having been brought on to the 

 premises for some months does not of itself justify a definite 

 conclusion that an outbreak of disease is not swine-fever. 



Post-Mortem Appearances. — The carcases of pigs which have- 

 died of swine-fever may or may not be emaciated, and purple 

 patches may be present on the skin of the ears, belly and hocks.. 

 In the acute cases characterised by death after a short period of 

 illness, redness of the lymphatic glands is observed, there are 

 signs of inflammation on the mucous membrane of the intestines,, 

 while the membrane is often dotted over with innumerable 

 red blood spots. These small haemorrhages, however, are not 

 peculiar to the very acute forms, and they may also be seen 

 in the more chronic cases. In the more chronic forms one 

 finds a diphtheritic deposit in the form of a yellowislr 

 (3864) Y 



