204 POULTRY DISEASES AND THEIR TREATMENT. 



anesthesia before the operation, if extensive, can be completed. 

 If, on the other hand, the anesthetic is given less freely the bird 

 .does not lose its reflex excitability. Every time a cut is made or 

 a nerve is pinched with the forceps the bird will struggle. Our 

 experience in anesthetizing birds, which has now covered a large 

 number of individuals, leads us to believe that the only middle 

 ;ground between these two extremes is afforded by those cases 

 (unfortunately too few) in which the individual idiosyncrasy of 

 the bird toward ether makes it take the anesthetic well. 



While we have made no detailed physiologic study as to the 

 fundamental reasons underlying this difficulty respecting anes- 

 thesia which has been described, it seems reasonably apparent 

 what these reasons are. Connected with the respiratory organs 

 proper of a bird are the relatively enormous air sacs. During 

 anesthesia the ether or chloroform vapor gets into these air sacs 

 either by diffusion or directly as a result of respiratory move- 

 ments. There is reason to believe that the vapor, once in the 

 air sacs, stays there until it is absorbed by the tissues ; in other 

 words, it appears to be the case that the great bulk of an inhaled 

 anesthetic in the case of birds must be eliminated from the body 

 by way of the urinary organs rather than the respiratory or- 

 gans. Assuming this to be the case there is no difficulty in see- 

 ing why forcing an anesthetic in a bird leads to disastrous re- 

 sults. The relatively enormous area for absorption afforded by 

 the air sacs insures that a correspondingly large amount of the 

 anesthetic will be taken up very quickly. This almost imme- 

 diately affects the vagus center, with the consequent cardiac 

 inhibition, respiratory failure and death. 



The exact method of procedure which we now follow in an- 

 esthetizing birds is as follows : Immediately before beginning 

 the administration of the anesthetic a 1-200 grain atropin sul- 

 phate tablet is dissolved in i c. c. of warm normal saline solu- 

 tion. The salt solution with the dissolved atropin is then in- 

 jected subcutaneously in the axilla. Ether is used as the anes- 

 thetic. It is administered from a small improvised mask which 

 admits of the condition of the comb being seen during the opera- 

 tion. Depending on how hard the ether is pushed, the bird is 

 ready for operation in from 15 to 20 minutes after the 

 anesthesia is begun. The dosage of 1-200 grain atropin to a 

 bird may seem large, but we have never been able to see the 

 slightest bad effect from it, provided the administration of ether 

 was begun immediately after the injection of the atropin." 



