THE DIGESTIVE SYSTEM. 239 



tliickeniDg and obliteration of its folds. The most fre- 

 quent cause is injury from too large a pellet or mass of 

 food being swallowed^ or from excessive force applied to 

 the impacted body by the probang in cases of choking. A 

 lesion of this nature follows corrosive poisonings and may 

 necessitate destruction of the patient after recovery from 

 the toxic effects of the agent. Dilatation of the tube 

 above the stricture occurs as a complication. The thick- 

 ening may extend along a considerable portion of the 

 lengtb of the oesophagus as a result of inflammation. 



Symptoms. — Swelling along tbe channel of the neck, 

 frequent choking, and attempts to vomit. More or less 

 impediment to swallowing and accumulation of food above 

 the stricture, giving rise to a swelling, which, largest at 

 first after feeding, gradually disappears until after the 

 next meal. 



Treatment has been successfully adopted in sucb cases 

 in the horse, but the method suggested for dilatation 

 should be adopted in the ox. The passage of probangs, 

 of gradually increasing size, periodically, may be tried in 

 cases of circumscribed stricture; stimulation, by means 

 of a blister, will tend to remove lymphy deposit. When 

 the stricture involves the thoracic portion of the oeso- 

 phagus (or its terminal extremity), it is even less amenable 

 to treatment. When due to pressure of a tumour it 

 may be cured by surgical removal of the cause. Certain 

 parasites — Spiroptera scutata oesophagea hovis — take up 

 their abode in the mucous membrane of the oesophagus. 

 They have not been observed in this country, but Miiller 

 gives an account of them (see ^Veterinarian,^ vol. xliii, 

 p. 632). They may cause stricture. 



RuPTUEE OP THE CEsoPHAGUs rcsults from force applied 

 from within, as when the probang slips round the impacted 

 body, or forces it through the wall of the tube. Lacerated 

 or punctured wounds from without, or extension of ulcera- 

 tion, too, cause perforation. An abscess has been known 

 to burst into the thoracic portion of the oesophagus, and 

 thus evacuate its pus. In these cases there are two un- 

 satisfactory points : first, the food constantly tends to 



