SUNSTROKE. 573 



during mid-summer in India, if we apportion the work of, say, the 

 first hour, so that the horse's skin recovers its normal function, acts 

 freely and then is allowed to dry while the animal is kept at an 

 easy pace, he will after that, if in " condition," be able to go at 

 least three times the distance he could have done, had he been 

 given no prelim inaiy preparation. 



Deprivation of water is a strong predisposing cause of sunstroke, 

 in that it cuts off the supply of the fluid by the evaporation of 

 which, in the form of perspiration, the body is kept cool. Among 

 other predisposing causes, we have : residence in a stable which 

 is ill-ventilated, crowded, or which does not afford adequate pro- 

 tection against the direct rays of the sun ; too much corn ; and 

 an insufficiency of green food. 



CLIMATE. — The climate most favourable to the development of 

 sunstroke, is a very hot one which, like that of Calcutta, has a 

 sufficiency of moisture in it to check the cooling influence, on 

 the body, of the evaporation of perspiration. The glare of the 

 sun off buildings and roads appears to help in bringing on an 

 attack. 



BREED AND TEMPERAMENT.— The horses most predisposed 

 to sunstroke are naturally those which have been bred in a 

 temperate or cold climate, especially if they have little or no 

 Eastern or thoroughbred blood in their veins. From my own 

 observations I believe that the internal temperature of Indian 

 Country Breds is, as a rule, lower than coarse-bred horses, whose 

 skin and hair are thicker and their sweat-glands less active than 

 those of Indian Country Breds, Arabs, and thoroughbreds. Con- 

 sequently they cannot keep themselves so cool, as better bred 

 horses. I have observed that horses which perspire little, are 

 .specially liable to sunstroke. Excitable, hard-pulling horses will 

 naturally be more apt to suffer from heat exhaustion than more 

 placid-tempered animals. 



PREVENTIVE MEASURES.— The predisposing causes should 

 be guarded against. Before taking a horse out to work, in a 

 climate and during weather in which sunstroke is liable to occur, 

 his breathing and general state should be observed. If he be seen 

 to "blow," he should be put back, and should be treated as the 

 case may demand. On a journey, under similar conditions, any 

 unusually quickened breathing and unwonted depression should at 

 once be attended to. In such instances the clinical thermometer 

 (p. 681) will be very useful. A rise of say 5° F. will point to 

 the existence of serious danger. Horses which have to work 



