DISEASES OF HORSES 387 



SUNSTROKE, HEAT STROKE, OR HEAT EXHAUSTION. 



The term sunstroke is applied to affections occasioned not ex- 

 clusively by exposure to the sun's rays, as the word signifies, but by 

 the action of great heat combined generally with humid atmo- 

 sphere. Exhaustion produced by a long-continued heat is often 

 the essential factor, and is called heat exhaustion. Horses on the 

 race track undergoing protracted and severe work in hot weather 

 often succumb to heat exhaustion. Draft horses exposed to the di- 

 rect rays of the sun for many hours, which do not receive proper 

 care in watering, feeding, and rest in shady places, suffer very fre- 

 quently from sunstroke. 



Symptoms. Sunstroke is manifested suddenly. The animal 

 stops, drops his head, begins to stagger, and soon falls to the ground 

 unconscious. The breathing is marked with great stertor, the pulse 

 is very slow and irregular, cold sweats break out in patches on the 

 surface of the body, and the animal often dies without recovering 

 consciousness. The temperature becomes very high, reaching 105 

 to 109 F. 



In heat exhaustion the animal usually requires urging for some 

 time previous to the appearance of any other symptoms, generally 

 perspiration is checked, and then he becomes weak in his gait, the 

 breathing hurried or panting, eyes watery or bloodshot, nostrils 

 dilated and highly reddened, assuming a dark, purple color; the 

 pulse is rapid and weak, the heart bounding, followed by uncon- 

 sciousness and death. If recovery takes place, convalescence ex- 

 tends over a long period of time, during which inco-ordination of 

 movement may persist. 



Pathology. Sunstroke, virtually active congestion of the brain, 

 often accompanied by effusion and blood extravasation, characterizes 

 this condition, with often rapid and fatal lowering of all the vital 

 functions. The death may be due in many instances to the complete 

 stagnation in the circulation of the brain, inducing anemia, or 

 want of nourishment of that organ. In other cases it may be directly 

 due to the excessive compression of the nerve matter controlling the 

 heart's action, and cause paralysis of that organ. There are also 

 changes in the composition of the blood. 



Treatment. Under no circumstances is bloodletting permis- 

 sible in sunstroke. Ice or very cold water should be applied to the 

 head and along the spine, and half an ounce of carbonate of am- 

 monia or 6 ounces of whiskey should be given in 1 pint of water. 

 Cold water should 'be showered upon the body of the horse from the 

 hose or otherwise. This should be continued until the temperature 

 is down to 103 F. Brisk friction of the limbs and the application 

 of spirits of camphor often yield good results. The administration 

 of the stimulants should be repeated in one hour if the pulse has not 

 become stronger and slower. In either case, when reaction has oc- 

 curred, preparations of iron and general tonics may be given during 

 convalescence: Sulphate of iron, 1 dram; gentian, 3 drams; red 

 cinchona bark, 2 drams; mix and give in the feed morning and 

 evening. 



