540 



A Manual of Veterinary Physiology. 



wholly under the nervous system. Therefore, by the action 

 of the vaso-motor nerves on the vessels of the skin, and the 

 secretory nerves governing the sweat-glands, the discharge 

 of heat is regulated. But the nervous system has yet a 

 third effect over animal heat. It is believed that certain 

 centres exist in the central nervous system which are in 

 connection with the muscles, and which by reflex action 

 regulate the metabolism of the tissues, and so increase or 

 decrease the amount of heat produced in the part. 



The normal temperature of the body in various animals 

 is as follows : 



Horse - 100° Fahr. 



Ox - - 100° to 101° (Colin). 



Sheep - 103° to 104°. 



Slight variations are found to occur in the temperature 

 during the twenty-four hours, which have been attributed 

 to the intake of food. The evening temperature is normally 

 higher than that found in the morning. Siedamgrotzky 

 found the highest temperature to be at six o'clock in the 

 evening, and the lowest at four o'clock in the mornin". 



The same observer studied the influence of feeding on 

 temperature : he found that the temperature rose '4° to 

 1'4° Fahr. after feeding, falling to normal in three to five 

 hours. Drinking a pailful of water at a temperature of 

 .")0° Fahr. caused the body temperature to fall 5° to 

 •9 Fahr. 



Feeding and drinking act antagonistically, so that one 

 balances the other. 



Exercise raises the body temperature, but to a very 

 variable extent in different horses. Half an hour's trotting 

 raised the temperature 7° to '2-7° Fahr. After work the 

 temperature at first falls rapidly, and then slowly. In 

 horses which have sweated profusely the resulting fall in tem- 

 perature carries it below the normal. - 



During diseased processes the temperature may run up 



Bee Siedamgrotzky's interesting paper, for which [am indebted to 

 a translation which appeared in the Veterinary .lor, nil, vol. i., L875. 



