SUNSTROKE 635 



SUNSTROKE (HEAT STROKE) 



Hogs are particularly susceptible to the effects of the rays of the 

 sun and to overheating. This is especially the case with fat ani- 

 mals. It is always dangerous to try and handle a fat hog on a hot 

 day, as the least exertion may produce a fatal overheating. This 

 should be remembered in the administration of hog-cholera serum, 

 and where fat hogs arc to be treated in hot weather the work should 

 be commenced as early in the morning as possible. 



When hogs are hauled to market in hot weather or shipped 

 in overcrowded care there is great danger of overheating and 

 death. In like manner, hogs that are kept in feed lots or pastures 

 that have no shade suffer extremely with the heat on a hot day. 

 This is in part due to the large amount of fat, and also to the fact 

 that the skin of the hog offers no protection against the direct action 

 of the rays of the sun. 



Where animals are allowed to overcrowd in a wagon, car, or 

 shed, they may suffer from heat prostration which is due to simple 

 overheating, and not to the effects of the rays of the sun. 



Just why the rays of the sun or the overheating of the body 

 from other causes should produce the symptoms seen in these con- 

 ditions is rather hard to understand. Some authors believe that 

 the effects are largely due to some chemical action of the rays of the 

 sun upon the nervous system. A more plausible explanation is 

 the theory that the heat of the sun is so marked in these cases that 

 it causes excessive heating of the central nervous system, and in 

 this manner produces paralysis of circulation and respiration. 



Symptoms. — The symptoms of overheating and sunstroke are 

 so nearly the same that there is little need of trying to make a dis- 

 tinction between the two. The animal will in some cases show no 

 evidence of the oncoming attack until suddenly noted to wobble and 

 fall over in a convulsion. In most cases there are a few warning 

 signs. The animal begins to droop, the ears fall forward, the gait 

 becomes uncertain, and, finally, the animal topples over uncon- 

 scious and is seized by a convulsion. Unless relief is promptly 

 given death very quickly takes place. 



If an examination of the pulse be made, it will be found to be 

 very rapid and weak. The temperature is very high, often rising 

 to 110° or 112° F. in cases of sunstroke. 



