DISEASES OF HORSES 367. 



Generally, however, it is associated with an attack of influenza, rheu- 

 matism, pleuritis, etc. 



Symptoms. Usually the disease manifests itself abruptly by 

 a brief stage of chills coincident with pain in moving, a short pain- 

 ful cough, rapid and short breathing, and high temperature, with 

 a rapid and hard pulse. In the early stages of the disease the pulse 

 is regular in beat; later, when there is much exudation present in 

 the pericardial sac, the heart-beat becomes muffled, and may be of 

 a double or rebounding character. By placing the ear against the 

 left side of the chest behind the elbow a rasping sound may be heard, 

 corresponding to the frequency of the heart-beat. This is known as 

 a friction sound. Between the second and fourth days this sound 

 may disappear, due to a distension of the pericardium by an exu- 

 date or serous effusion. As soon as this effusion partly fills the 

 pericardium, percussion will reveal an abnormally increased area 

 of dullness over the region of the heart, the heart-beats become less 

 perceptible than in health, and in some cases a splashing or flap- 

 ping sound may become audible. 



If the effusion becomes absorbed, the friction sound usually 

 recurs for a short time ; this friction may often be felt by applying 

 the hand to the side of the chest. In a few cases spasms of the 

 muscles of the neck may be present. In acute pericarditis, when the 

 effusion is rapid and excessive, the animal may die in a few days 

 or recovery may begin equally as early. In subacute or in chronic 

 cases the effusion may slowly become augmented until the pressure 

 upon the lungs and interference with the circulation becomes so 

 great that death will result. Whether the attack is acute, subacute, 

 or chronic, the characteristic symptoms which will guide us to a 

 correct diagnosis are the friction sound, which is always synchro- 

 nous with the heart's action, the high temperature with hard, irri- 

 table pulse, and, in cases of pericardia! effusion, the increased area 

 of dullness over the cardiac region. When the disease is associated 

 with influenza or rheumatism, some of the symptoms may be ob- 

 scure, but a careful examination will reveal sufficient evidence upon 

 which to base a diagnosis. When pericarditis develops as a result 

 of or in connection with pleuritis, the distinction may not be very 

 clearly definable, neither will many recover. When it results from 

 a wound or broken rib, it almost invariably proves fatal. 



Pathology. Pericarditis may at all times be regarded as a 

 very serious affection. At first we will find an intense injection or 

 accumulation of blood in the vessels of the pericardium, giving it 

 a red and swollen appearance, during which we have the friction 

 sound. In twenty-four to forty-eight hours this engorgement is 

 followed by an exudation of sero-fibrinous fluid, the fibrinous portion 

 of which may soon form a coating over the internal surface of the 

 pericardial sac, and may ultimately form a union of the opposing 

 surfaces. Generally this adhesion will only be found to occupy a 

 portion of the surfaces. As the serous or watery portion of this 

 effusion is absorbed, the distinctness of the friction sound recurs, 

 and may remain perceptible in a varied degree for a long time. 



