AZOTUEIA 109 



point, we believe that the condition in azoturia is first , 

 ,a Yiscosity of the blood; later, if the condition does not 

 abate, genuine clotting or thrombosis in the vessels of the I 

 parts involved. Death occurs either early as the result 

 of embolism, or late from decubitus and its accompani- 

 ments. Carefully follow the form below, in which we 

 work out the theory. 



" 1. A horse at rest a number of days on full rations. 



"2. A modified atony of the muscular coats of the ves- 

 sels results, accompanied by a hyper-nitrogenous condi- 

 tion of the blood and internal secretions. 



"3. In adverse ratio to this atony is the accelerated 

 tone of nervous elements, causing the horse to 'feel 

 good,' as it is commonly expressed. 



"4. When this horse is put to work he is keyed up to 

 the highest pitch as regards volition; in other words, 

 he has ambition forced upon him by the heightened tone 

 of his nervous system. (Here could be inserted the rea- 

 son why the disease does not occur or is so rare in 

 summer.) 



"5. Responding to this stimulation the cardiac action 

 as a result of a few minutes' exercise assumes the force 

 which it would, under normal conditions, attain only at 

 the end of the most strenuous exertion, at running or 

 severe pulling in harness. This does not produce objec- 

 tive tachycardia because of the flaccid condition of the 

 muscular apparatus of the vessels. 



"6. From this atony or flaccidity the vessels in the 

 extremities are the last to recover; in fact, if the horse 

 is not stopped at once they (the vessels) do not recover. 

 Gravity plays a slight part here. 



"7. Soon there is a real blocking of the circulation in 

 these parts. 



"8. The large muscles in the region attempt to assist 

 the vasoconstrictors; they contract in a firm spasm 



