70 



Scientific Proceedings (32). 



It responds to a call very slowly, and sometimes falls into a sleep, 

 from which it is aroused with difficulty. Actual coma sets in at a 

 point immediately following the decline in the pulse rate, or when 

 about 50 per cent, of the hemoglobin is saturated with carbon 

 mon-oxide. This has been found to be constant in all cases. 



Death also takes place in all dogs at about the same point of 

 saturation. Not a single one reached the 75 per cent. mark. All 

 died between 71 and 74 per cent, of saturation of the hemoglobin 

 with carbon mon-oxide. Neither size, weight nor strength seemed 

 to influence the point of death. 



From the foregoing it is seen that the symptoms of carbon 

 mon-oxide poisoning may be conveniently divided into three 

 stages : First or Compensatory Stage, which lasts up to 50 per 

 cent, saturation ; second or Stage of Depression which lasts up to 

 about 70 per cent, saturation ; third or Stage of Collapse. 



Symptoms of the First or Compensatory Stage. 



1. Gradual increase in pulse rate. 



2. High blood pressure. 



3. Spasmodic attacks of vomiting, 



4. Slight dyspnoea at first — more marked at the end. 



5. Muscular weakness. 



6. Drowsiness, indifference and deep sleep from which dog can be 



aroused. 



Symptoms of the Second or Stage of Depression. 



1. Ushered in by clonic convulsion and muscular rigidity which 



lasts for a few minutes. 



2. Deep narcosis from which animal cannot be aroused. 



3. Pulse declines gradually in rate, tension and volume. 



4. Respiration either rapid and shallow, or slow and deep; it is 



more or less regular. 



5. Absolute loss of sensation. 



Symptoms of the Third or Stage of Collapse. 



1. Pulse slow, irregular and of low tension. 



2. Respiration irregular. 



3. Loss of tone of sphincters. 



4. Conjunctival reflex lost. 



5. Death due to respiratory paralysis. 



