242 THE PULSE. 



them, and by which also they contract again as soon as the stream has passer] 

 the middle coat is a muscular one, hy which this contraction is more powerfully 

 performed, and the blood urged on in its course; the inner or membranous 

 coat is the mere lining of the tube. 



This yielding of the artery to the gush of blood, forced into it by the con- 

 traction of the heart, constitutes 



THE PULSE. 



The pulse is a very useful assistant to the practitioner of human medicine, 

 and much more so to the veterinary surgeon, whose patients cannot describe 

 either the seat or degree of ailment or pain. The number of pulsations in any 

 artery will give the number of the beatings of the heart, and so express the 

 irritation of that organ, and of the frame generally. In a state of health, the 

 heart beats in a fanner's horse about thirty-six times in a minute. In the 

 smaller, and in the thorough- bred horse, the pulsations are forty or forty-two. 

 This is said to be the standard pulse, the pulse of health. It varies singularly 

 little in horses of the same size and breed, and where it beats naturally there can 

 be little materially wrong. The most convenient place to feel the pulse, is at 

 the lower jaw (p. 108) a little behind the spot where the submaxillary artery 

 and vein, and the parotid duct, come from under the jaw. There the number 

 of pulsations will be easily counted, and the character of the pulse, a matter of 

 fully equal importance, will be clearly ascertained. Many horsemen put the 

 hand to the side. They can certainly count the pulse there, but they can do 

 nothing more. We must be able to press the artery against some hard body, 

 as the jaw-bone, in order to ascertain the manner in which the blood flows 

 through it, and the quantity that flows. 



When the pulse reaches fifty or fifty-five, some degree of fever may be 

 apprehended, and proper precaution should be taken. Seventy or seventy-five 

 will indicate a dangerous state, and put the owner and the surgeon not a little 

 on the alert. Few horses long survive a pulse of one hundred, for, by this 

 excessive action, the energies of nature are speedily worn out. 



Some things, however, should be taken into account in forming our conclusion 

 from the frequency of the pulse. Exercise, a warm stable, and fear, will won- 

 derfully increase the number of pulsations. 



When a careless, brutal fellow goes up to a horse, and speaks hastily to him, 

 and handles him roughly, he adds ten beats per minute to the pulse, and will 

 often be misled in the opinion he may form of the state of the animal. A judi- 

 cious person will approach the patient gently, and pat and soothe him, and even 

 then the circulation, probably, will be little disturbed. He should take the 

 additional precaution of noting the number and quality of the pulse, a second 

 time, before he leaves the animal. 



If a quick pulse indicate irritation and fever, a slow pulse will likewise 

 characterise diseases of an opposite description. It accompanies the sleepy stage 

 of staggers, and every malady connected with deficiency of nervous energy. 



The heart may not only be excited to more frequent, but also to more violent 

 action. It may contract more powerfully upon the blood, which will be driven 

 with greater force through the arteries, and the expansion of the vessels will be 

 greater and more sudden. Then we have the hard pulse, the sure indicator of 

 considerable fever, and calling for the immediate and free use of the lancet. 



Sometimes the pulse may be hard and jerking, and yet small. The stream 

 though forcible is not great. The heart is so irritable that it contracts before 

 the ventricle is properly filled. The practitioner knows that this indicates a 

 dangerous state of disease. It is an almost invariable accompaniment of 

 inflammation of the bowels. 



