DISEASES OF HORSES 19 



nutrition is shown by the pliability and softness of the skin, and the 

 tone of the hair. If the subcutaneous fat has disappeared and the 

 muscles are wasted, allowing the bony prominences to stand out; if 

 the skin is tight and inelastic and the coat dry and harsh, we have 

 evidence of a low state of nutrition. This may have resulted from a 

 severe and long-continued disease or from a lack of proper food and 

 care. Where an animal is emaciated that is, becomes: thin there is 

 first a loss of fat and later the muscles shrink. 



The temperament of a horse is indicated by the manner in which! 

 he responds to external stimuli. When the horse is spoken to, or. 

 when he sees or feels anything that stimulates or gives alarm, if he 

 responds actively, quickly, and intelligently, he is said to be of lively, 

 or nervous, temperament. On the other hand, if he responds in a 

 slow, sluggish manner, he is said to have a sluggish, or lymphatic, 

 temperament. The temperament is indicated by the gait, by the ex- 

 pression of the face, and by the carriage of the head and ears. The 

 nature of the temperament should be taken into consideration in an- 

 endeavor to ascertain the severity of a given case of illness, because 

 the general expression of an animal in disease as well as in health de- 

 pends to a large extent on the temperament. 



The Skin and the Visible Mucous Membranes. The condition 

 of the skin is a fair index to the condition of the animal. There is no 

 part of the body that loses its elasticity and tone as a result of disease 

 sooner than the skin. Similarly, the condition of the animal is shown 

 to a certain extent by the appearance of the mucous membranes. For 

 example, when the horse is anemic as a result of disease or of inap- 

 propriate food the mucous membranes become pale. This change in 

 the mucous membranes can be seen most readily in the lining of the 

 eyelids and in the lining of the nostril. For convenience of exam- 

 ination the eyelids can readily be everted. Paleness means weak cir- 

 culation or poor blood. Increased redness occurs physiologically in 

 painful conditions, excitement, and following severe exertion. In 

 fevers there is an increased redness in the mucous membrane, and 

 this continues so long as the fever lasts. In some diseases red spots or 

 streaks form in the mucous membrane. This usually indicates an 

 infectious disease of considerable severity, and occurs in blood poison- 

 ing, purpura hemorrhagica, and hemorrhagic septicemia. When the 

 liver is deranged and does not operate, or when the red-blood cor- 

 puscles are broken down, as in serious cases of influenza, there is a 

 yellowish discoloration of the mucous membrane. The mucous mem- 

 branes become bluish or blue w r hen the blood is imperfectly oxidized 

 and contains an excess of carbon dioxide. This condition exists in 

 any serious disease of the respiratory tract, as pneumonia, and in 

 heart failure. 



The temperature of the skin varies with the temperature of the 

 body. If there is fever the temperature of the skin is likely to be 

 increased. Sometimes, however, as a result of poor circulation and 

 irregular distribution of the blood, the body may be warmer than 

 normal, while the extremities (the legs and ears) may be cold. Where 

 the general surface of the body becomes cold it is evident that the 



