MORBID ANATOMY 



271 



walls of the arteries are spasmodically tense. In many cases, 

 however, it is full, soft and easily compressible. There is, as 

 a rule, an increase in the number of respirations, which may 

 become very high if the respiratory muscles are attacked. 

 The number varies according to the excited condition of the 

 animal. The respirations may increase four fold without a 

 corresponding increase in the pulse beat. The breathing may 

 reach from 80 to 100 per minute. In character the respirations 

 are shallow on account of the fixed condition of the ribs and 

 the spasms of the muscles which compress the abdomen. 

 There may be cyanosis and catarrh of the nasal mucosa, 

 coughing and in fatal cases symptoms of hyperemia and edema 

 of the lungs and often pneumonia (usually aspiration in 

 nature). There is constipation due to lack of peristalsis and 

 the rigid condition of the muscles which compress the 

 abdomen. Micturition becomes less frequent and more diffi- 

 cult. Complete retention of urine is said to occur in some 

 cases. The urine has a high specific gravity and occasionally 

 contains albumen. Some animals can eat readily while others 

 eat, if at all, with great difficulty. They like to play with 

 drink set before them and often try to satisfy their thirst, 

 which seems to increase as the disease advances. In fatal 

 cases the animals seem to be perfectly conscious to the last. 

 They seem to be possessed of a feeling of terror. 



§ 194. Morbid anatomy. The gross examination of 

 the tissues at post-mortem of animals dead from tetanus is 

 usuall}' negative. It has been pointed out by Goldscheider 

 and Flatau that in experimental animals there are certain 

 characteristic changes in the motor cells of the anterior horns 

 of the spinal cord which in the order of their development 

 depend upon the concentration of the toxin or virulence of the 

 bacteria injected and upon the duration of the disease. The 

 changes are primarily an enlargement of the nuclei, which at 

 the same time become more distinct ; then follows an enlarge- 

 ment and disintegration of Nissl's cell-granules with an 

 enlargement of all of the nerve cells. These investigators also 



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