176 DISEASES OF SWINE 



in strength there is also a rapid increase in loss in weight, and the 

 animal quickly becomes very gaunt and drawn up. The weakness 

 finally becomes so marked that the animal is absolutely unable 

 to rise or stand, even if placed upon his feet, and finally death re- 

 lieves him from his suffering, usually taking place during the night. 



Breathing and Pulse. — Early in the disease there is not very 

 much interference with the breathing, but later on, especially in 

 those cases where the lungs are very much affected, the breathing 

 becomes very rapid and short. In some cases the tissues around 

 the throat become quite swollen, and this swelling, by pressure 

 upon the wind-pipe, increases the difficulty of breathing. In such 

 cases the breathing becomes very noisy as well as rapid. 



When the virus of hog-cholera begins to multiply in the body 

 of the animal, the poisons produced are taken into the blood and 

 carried to the heart. The effects of these toxins or poisons are to 

 irritate the heart and make it beat more rapidly. This causes the 

 pulse to become more rapid, and at the same time it is more full 

 and bounding, due to the increased force of the heart-beat. 



Later on in the disease the amount of the poisonous material 

 in the blood becomes so great that it simply poisons the heart, 

 until that organ is no longer able to stand up under the strain. 

 As a result, it begins to beat more rapidly than ever, but at the 

 same time gets very feeble and weak in character and soon wears 

 itself out. In the last few hours of the disease the heart-beat 

 becomes exceedingly rapid and weak, and often the pulse can 

 scarcely be felt at all. Death probably is the result of actual wear- 

 ing out and failure of the heart muscle, due to the poisonous effects 

 of the toxins produced by the hog-cholera virus. 



Thumping.^In a severe case of cholera, when the respiration 

 or breathing becomes very rapid, it is not unusual for the sick ani- 

 mal to develop a case of thumps. This thumping is due to a spasm 

 of the midriff or diaphragm, which is the large fan-shaped muscle 

 which separates the organs of the chest from those of the belly. 

 This muscle has a very important part to do with breathing, and 

 when the breathing becomes too rapid, as in hog-cholera, it goes 

 into a spasm, and we then have the familiar condition known as 

 thumps, in which at each respiration there is a spasmodic drawing 

 in of the hind ribs. Thumps is much more likely to occur in pigs 



