692 OPERATIONS. 



The indications afforded by the olinioal thermameter are yaluable 

 guides as to the state of the animal's health at the time, or to 

 what it will shortly be. Thus, in a horse at rest under ordinary 

 conditions, if there be a rise of three or four degrees without the 

 animal evincing any other sign of illness, we may be assured that 

 disease in some form will, after a day or two, manifest itself in 

 him. During illness, a temperature of, say, 106° F. or more, 

 points to a condition of great danger. 



The clinical thermometer is specially useful for indicating the 

 state of a horse during infective diseases and diseases of the 

 organs of breathing. A fall in the temperature, when it has been 

 abnormally high, will generally point to a favourable termination 

 of the disease ; although in some cases it is the precursor of rapidly 

 approaching death. 



TEMPERATURE DURING HEALTH.— As a rule, there is a 

 daily variation in the internal temperature of a healthy horse, of 

 about 1° F. ; the maximum being attained at about 5 o'clock in the 

 evening. In the adult horse, the temperature is about 1° F. higher 

 than in a very young or a very old animal. It is about 1° F. less 

 in the mare than in the horse, except when she is " in season," 

 during which time it is about 2° F. higher than normal. The 

 temperature of thorough-breds is higher than that of common 

 horses. A rise of 4° or 5° F., compatible with health, may be 

 observed in horses doing violent work in hot weather. The tem- 

 perature of well-fed horses is higher than that of poorly-fed ones. 

 During digestion it rises about 1° F., and falls about the same 

 amount during sleep. Nocard shows that exposure to the rays of 

 a hot sun for a few hours may cause a rise of as much as 3.5° F., 

 and the effects of cold and rain may equally lower it. I have often 

 seen horses in India and South Africa have a temperature of 105° 

 F., without any derangement to their health, when they were 

 picketed in the open during hot weather. 



The average internal temperature of a healthy horse is about 

 100° F., varying, say, from 99° to 101° F. Cad6ac puts it at 

 from 99.5° to 100.4° F. Professor Hobday finds that the average 

 temperature is 100.3° F. As an approximation, we may say that 

 a rise or fall of more than 2° F. is not compatible with health, 

 unless there have been specially exciting causes. Referring to 

 India, Haslam states that among healthy horses at rest, the range 

 of temperature is from 98.5° to 100.5° F. ; and among apparently 

 healthy, though poorly-fed " grass-cutters' " ponies, from 97 4° 

 to 101.4° F. 



