570 NEKVOUS DISEASES. 



SYMPTOMS. — The history is, generally, somewhat as follows : 

 The horse, who, in many cases, had been previously dull and 

 breathing quickly (with, of course, distended nostrils), v is taken 

 out to -work, which he does fairly well (although an experienced 

 person would observe that he was much more distressed than he 

 ought to have been), until, more or less suddenly, he totters ; his 

 legs give way under him ; and he falls down in an insensible con- 

 dition. He may then struggle convulsively, get up and throw 

 himself down in a most dangerous manner ; or, while lying on the 

 ground, make frantic efforts to get up, which he is unable to do 

 owing to his being paralysed behind, and madly dash his head on 

 the ground. In these convulsive efforts, he often inflicts terrible 

 injuries on himself. Paralysis of the hind quarters is a well- 

 marked symptom of sunstroke in the horse. Others will remain 

 lying down, as if dead : these are the hopeful cases. In all such 

 instances, the animal is unconscious of external impressions, which 

 fact will serve to distinguish this disease from hsemoglobinuria 

 (p. 504). The temperature is high. The eyes are staring, but 

 they evidently do not see, because their surface can be touched by 

 the finger with little or no wincing, on the part of the patient, 

 from the contact. Apparently, head symptoms predominate. 

 The breathing is shallow and greatly quickened, and in bad 

 cases the pulse is so frequent and weak that it is all but 

 imperceptible. The skin may be dry, or partially covered with 

 perspiration. In severe cases, the muscles over the whole surface 

 of the body will often be in a state of continued tremor. If the 

 disease is going to run a fatal course, it will usually do so within 

 about six hours. Some horses apparently get all right after an 

 attack of sunstroke, but begin to " blow " again in a few hours, in 

 which case they generally die from congestion of the lungs. When 

 a horse which has fallen down from sunstroke gets up, he may be 

 regarded as convalescent. Horses that drop from sunstroke do so, 

 as a rule, after 2 or Sio'clock in the afternoon. 



CAUSES. — Although I have seen heat apoplexy during very hot 

 weather, affect horses travelling by rail in open trucks, and others 

 kept in ill-ventilated stalls ; such cases were so few in number com- 

 pared to those struck down during work, that fatigue must be 

 regarded as a marked accessory cause. I have never known a 

 horse get sunstroke, .in the first instance, from standing in the 

 open, no master how hot the weather may have been, provided that 

 he had the advantage of shade which, like that of a tree with good 

 foliage overhead, did not interfere with the circulation of air. 

 The Tramway Company of Calcutta (in which city cases of equine 

 sunstroke are very common in the summer), by reducing during 



