PERICARDITIS 73 



particular alteration at the orifices or valves, of the heart, 

 and are found in the different forms of anemia in animals. 



2. Pericardial Bruits.— These bruits consist of friction 

 sounds due to the pericardium becoming rough and dry. 

 These sounds can be distinguished, as they do not occur 

 synchronously with the heart sounds and are often indepen- 

 ent of them. They are noted in pericarditis where there is 

 not sufficient fluid to keep the membranes separated. They 

 must be distinguished from pleural friction sounds, and can 

 be quite readily, as they occur entirely independent of the 

 respiratory movements. 



From a clinical standpoint, in small animals, further 

 differentiation of the various heart bruits cannot be made. 



PERICARDITIS. 



Definition.— An acute or chronic inflammation of the peri- 

 cardium. 



Etiology.— Inflammation of the pericardium may originate 

 primarily or secondarily. 



Primary pericarditis may result from : (a) Trauma, which 

 may originate from within, such as the passage of foreign 

 bodies (needles, pins, pieces of bone, etc.) through 'the esopha- 

 geal walls. This occurs most commonly in the dog and cat 

 from swallowing needles, pins, etc., during play. It may also 

 result from trauma from without, such as puncture wounds 

 through the thoracic walls, or from falling, being run over 

 by vehicles, etc. In such cases the pericardium is injured 

 directly or indirectly by being pressed upon by the displaced 

 thoracic wall or adjacent organs. 



(b) Infective processes which in some cases may be 

 primary or at least involve principally the pericardium. 

 Staphylococci, streptococci and the specific virus of dis- 

 temper are the most common organisms found. Primary 

 infection, however, is not a common etiological factor. 



(c) Cold has frequently been mentioned as one of the 

 causes of pericarditis. This should be considered simply 

 as a predisposing factor in lowering general resistance, which 

 allows the development of infection, etc. 



