136 DISEASES OF THE ESOPHAGUS 



Etiology. The most common causes of this condition are 

 the following: (a) Cicatricial contraction of healed ulcers, 

 usually due to corrosive poisons; injuries by foreign bodies, 

 etc. ; esophagotomy . (6) External pressure by enlarged lymph 

 glands, enlarged thyroids, other tumors and occasionally 

 pericardial effusion, (c) The growth of tumors in the walls 

 of the esophagus (metastatic sarcomas and carcinomas). 

 The stricture may occur in any part of the esophagus, and 

 in severe cases may involve the entire tube, but usually it is 

 found either near the pharynx or the stomach. 



Symptoms. Difficulty in swallowing and only small 

 quantities taken. Severe pain immediately after eating. 

 Retching and vomiting are often noticed. Gradual emacia- 

 tion due to the interference with deglutition. Examination 

 of the esophagus in the cervical region by palpation or the 

 passage of the sound to the thoracic region will usually reveal 

 the constricted condition of the esophagus. 



Prognosis. Should be considered unfavorable in all cases 

 of long standing. Recent cases, depending upon the cause, 

 may recover sufficiently not to interfere much with the 

 animal's general condition. 



Treatment. By surgical means the cause of the condition 

 should be removed if possible. The passage of the sound, 

 well lubricated, daily for a time will in some cases overcome 

 the constriction. In severe constrictions where a large por- 

 tion of the walls is involved no treatment can be applied that 

 will be of any service. 



DILATATIONS AND DIVERTICULA OF THE ESOPHAGUS. 



Definition. Dilatation is a diseased condition whereby 

 the lumen of the esophagus is enlarged (ectasia oesophagi). 

 A diverticulum is a saccular distention of the esophageal wall 

 at a given point along its course (diverticulum oesophagi). 



Etiology. Dilatation may develop secondary to stenosis of 

 the esophagus, from pressure of food masses retained above 

 the stenosis resulting in paralysis or atony of .the muscular 

 wall; from foreign bodies remaining in the esophagus for 

 sufficient length of time to produce paralysis; injuries; 



