ASPHYXIA. 49 



tation at an advanced stage of anaesthesia is a sign of bulbar 

 intoxication and of imminent syncope. 



When the corneal reflex is lost and the pupil contracted, 

 sensibility has disappeared, and muscular relaxation is complete. 

 Provided respiration and circulation continue regular, anaesthesia 

 can then be prolonged for periods of two or even three hours without 

 danger by occasionally administering further small doses of 

 chloroform. 



On completion of the operation the hobbles are removed ; but 

 the horse is left undisturbed until it rises of itself, which will usually 

 happen in a quarter to half an hour. Should the animal be forced 

 to rise before consciousness has entirely returned, it walks unsteadily, 

 " bores " forward like an animal with brain disease, and may fall. 

 To support it an assistant may walk on each side, with a hand on 

 the point of the hip, and one behind holding the tail. 



Administered with the foregoing precautions chloroform becomes 

 a perfectly safe anaesthetic for the horse, and though individual 

 animals show special susceptibility to its action, yet in general the 

 danger is infinitely less than was formerly imagined. 



Fatal issues result either from asphyxia or syncope. 



Asphyxia usually occurs during the period of excitation, 

 especially if some closed muzzle like the Carlisle muzzle or its modi- 

 fications be used ; first breathing stops, and after a short interval 

 the heart's action fails. 



Asphyxia may also happen towards the end of the anaesthetic 

 period if administration has been pushed far and is suddenly checked. 

 In such case the sides of the chest, face, or lips should be smartly 

 struck with the hand or a wet towel to provoke reflexes and restore 

 respiration. When arrest continues for an appreciable period (the 

 writer has timed arrests of thirty to forty-five seconds), artificial 

 respiration may be resorted to. A fairly heavy assistant stands 

 between the animal's legs and presses with his entire weight on the 

 animal's chest, rising again almost immediately. This is repeated 

 at intervals of about four or five seconds. The shock should not 

 be violent : but the man's whole weight should be employed, and 

 special attention must be given to regularity in the process. In the 

 horse it rarely happens that the tongue recedes and by covering 

 the opening of the larynx causes asphyxia. Should any indication 

 of this — like loud snoring, etc. — occur, the tongue should immediately 

 be grasped and drawn forward. 



In cases of respiratory failure some French investigators have 

 recommended the system practised in man for resuscitation 



