SECTION VII. 

 DISEASES OF THE CIRCULATORY SYSTEM. 



Diseases of this system no doubt occur much more frequently 

 than veterinarians suppose; they are probably overlooked in many 

 cases, owing to the deep situation of the heart, the thickness of the 

 skin, the presence of large muscles, and the difficulty of obtaining 

 results from the physical signs, and to otherwise examine the heart. 



The average number of pulsations per minute are (as stated 

 elsewhere) 36 to 40. 



The number of beats normally varies with the temperament, 

 age, work, etc. In the country, where quiet prevails, the number 

 of beats per minute is less and the arteries are more full, whereas 

 in cities the animals are called upon to do more rapid work, which 

 causes the number of heart-beats to be increased. 



PEEICAEDITIS. 



What are the forms? 



Pericarditis may be acute or chronic. 



ACUTE PEEICAEDITIS. 



Define acute pericarditis. 



It is an acute fibrinous inflammation of the pericardium and 

 is characterized by fever and a very rapid pulse. 



Give the aetiology. 



It may exist as an independent disease, but it is usually sec- 

 ondary to such diseases as pneumonia, pleurisy, purpura haemor- 

 rhagica, and certain of the infectious diseases. 



What is the pathology? 



The pathology is about the same as serous membranes in other 

 situations; for study, three stages are recognized: 



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