378 PERICARDITIS. 



whole mischief is in the abdominal cavity. The patients are dull, rest- 

 less, and seem to be suffering from an obscure ailment. They remain 

 standing more than usual, show more than ordinary deliberation in 

 lying down, lose appetite, cease to ruminate regularly, and exhibit 

 intermittent tympanites. 



The cause of these symptoms is as follows : At first the reticulum is 

 partly immobilised by the local inflammation, and at a later stage move- 

 ment of the diaphragm is checked by reflex action when the sharp body 

 has progressed far enough to touch it. The rhythmic movements of the 

 reticulum and the diaphragm are interfered with, rumination is dis- 

 turbed, eructation ceases, and tympanites appears. 



The patient often utters slight groans, particularly when forced to 

 move ; but as this is a sign common to all grave diseases it can only 

 give rise to a suspicion as to what has occurred. In ten to fifteen days 

 this primary phase may have terminated ; but it is impossible to say 

 how long it lasts, for it varies with each animal as with each variety 

 of foreign body, and it may be prolonged for months. 



From the moment it reaches the thoracic cavity the foreign object 

 makes its way towards the channel formed on either side by the ribs and 

 below by the sternum, and therefore towards the point of the heart. 

 This is the second phase of development. 



The passage of the foreign body through the diaphragm occupies a 

 more or less considerable time, depending on its length ; the beginning 

 of this second phase is characterised by relative immobility of the circle 

 of the hypochondrium during respiration. The abnormal sensibility and 

 pain impede contraction of the diaphragm. 



Palpation of the region of the xiphoid cartilage then reveals abnormal 

 sensibility, and sometimes causes the animal to resent being handled. 



From this time the pericardial symptoms proper commence, the 

 foreign body having come in contact with the pericardium. This phase, 

 unlike those which precede it, presents well-defined symptoms. The 

 irritation of the heart and its ganglionic system by a foreign body in the 

 pericardium is shown by considerable acceleration of the heart beats 

 even before there is any exudation into the pericardial sac. Instead of 

 60 to 70 beats, the normal number, the pulse may rise to 80, 90, 100, or 

 even 110 beats per minute. The heart sounds are tumultuous, dull and 

 ill-defined, while the pulse appears bounding and strong. 



But this period of cardiac excitement while persisting is soon com- 

 plicated by other symptoms. As soon as the foreign body penetrates the 

 pericardial sac, there is infection, which produces an active form of 

 inflammation and abundant exudation. From this time the pulse be- 

 comes weaker and weaker, until, under the steadily increasing pressure 

 on the heart, it is almost imperceptible. 



