DISEASE IN GENERAL 



147 



a most valuable guide for the early detection of disease. In the old 

 days the temperature of an animal was deter- 

 mined by simply laying the hand upon the body 

 of the patient. The ears, nose, and legs are the 

 first parts of the body to show temperature varia- 

 tions. With the thermometer we have a much 

 more accurate method of determination. A 

 maximum-registering thermometer is used, and 

 it must be carefully shaken down before insertion. 

 It is not possible to give an exact figure for the 

 temperature of the horse under normal condi- 

 tions as it is for man, because many influences 

 are at work. Experience shows that the limits 

 are from 100° F. as a minimum to 102° F. for 

 the maximum. Figure 46 is an illustration of a 

 thermometer designed especially for the horse; 

 the mercury stands at the average normal tem- 

 perature. In the heat of the summer, after 

 work in the sun, horses may show a temperature 

 of 103.5° F. and be perfectly normal. 



Three other aids in establishing a diagnosis 

 are the making of diagnostic inoculations, a post- 

 mortem examination, and a biologic examination. 



Diagnostic inoculations consist in the intro- 

 duction of certain substances into 'the bodies of 

 animals for the purpose of recognizing the disease 

 or of obtaining an early diagnosis. They are 

 only serviceable in those cases in which our ex- 

 amination leads us to suspect some infectious 

 disease, such as glanders. In this particular 

 disease mallein is injected under the skin or in- 

 stilled into the eye of the patient, or an ex- 

 perimental animal is inoculated with nasal 

 secretion, pus, etc., from the suspicious subject. 



A postmortem examination is often required 



to establish a positive diagnosis, especially where pjg 45 clinical 



one or two horses have died suddenly. In this thermometer, 

 work training and experience are called for to 

 distinguish between changes due to disease and those caused by 

 physical conditions. After death the blood gravitates to the lowest 



