Your Horse's Heart
When you first start examining patients as a veterinary student youre very keen to gently poke and prod every animal you come across. Realizing you can assess cardiovascular function by palpating peripheral pulses is very empowering!
Once you find a pulse in a healthy cow you simply hang on and count as the pulse waves come to you in a more or less steady stream 60 to 80 times a minute. You can confidently anticipate when the next one is going to arrive. Then you examine a horse perhaps a mare in her late teens quiet cooperative and relaxed and all of your confidence disappears. One minute you have the pulse the next you dont. One minute the pulse is strong then it disappears and youre sure you didnt move your fingers. The book says the rate should be 28 to 40 beats per minute but in this horse sometimes its 40 and sometimes its 12.
Cardiovascular Reserve and the Microcirculation
The cardiovascular system exists for no reason other than to meet the needs of tissues muscle for example and in this regard the heart is an essential but slavish bag of muscle a pump. It goes like this blood flows from areas of high pressure to areas of low pressure. The highest pressure is at the left ventricle of the heart during systole or contraction where the pressure is generated and its lowest in the right ventricle in diastole or relaxation when the right