90 THE HOESE AND ITS DISEASES. 



is seldom disease present without an alteration in tlie 

 arterial system, either accelerating the motion of the 

 blood, or retarding it, so it becomes always a very 

 important matter to ascertain the several states in which 

 the vessels concerned in circiilation may be. It is a 

 little remarkable, that though the horse's pulse is very 

 easily and conveniently felt from the branch of the 

 internal maxillary that runs over the posterior jaw, yet, 

 authors who have written, have either omitted it entirely, 

 or have given the most vague directions with regard to 

 it. Mr. Bartlet recommends feeling it by the leg. Mr. 

 Clark speaks of it as most easily felt at the origin of tho 

 temporal artery, at the base of the ear ; but it is nowhere 

 so conveniently observed as at the part 1 have described.. 



The pulse is slower in large animals than in small 

 ones, hence the pulse of a dog is from 80 to 110, accor- 

 ding to his size ; the pulse of a man is fi'om 65 to 70 ; 

 but in the horse, as a still larger animal, it is from 40 

 to 45. In young animals, the weakness of the system, 

 and its irritability, are considerable, hence, they have a 

 much quicker pulse. The cat's pulse is 70 to 80 ; the 

 human infant's beats more than 100; this gradually 

 lessens to the adult period, when it follows nearly the 

 standard we have noticed. As the heart of a large 

 animal has a longer way to send its blood, and its 

 resistance is consequently increased, so it takes a longer 

 time to accomplish its contraction ; and thus there is not 

 only a difference between the different species of animals, 

 but between individuals of the same species, as they 

 vaiy in size, from which, the smaller the horse, the 

 quicker the pulse. 



Many circumstances must be taken into consideration 

 in studying the pulse ; a particular irritability of the 

 system occasions a quickened pulsation ; fear, likewise, 

 generally occasions a very considerable increase' of it, 

 for which reason great caution is necessary not to alarm 

 the animal, or the pulsating vessel will present a wrong- 

 indication. 



