IMPACTION OF THE CROP IN BIRDS. 425 



oesophagus, may be pushed onwards with an expanding oesophageal 

 sound or a flexible catheter. This failing, emetics, such as apomor- 

 phine subcutaneously, may be tried, and, if unsuccessful, cesophag- 

 otomy which in dogs as in other animals is without danger, must 

 be performed. Moller often operated successfully. In one case 

 the oesophagus was perforated at two points, but the piece of 

 bone was removed, and healing followed without stricture or other 

 bad result. 



Coleman removed a rabbit's vertebra from the oesophagus of a 

 dog by incision. Complete healing in a fortnight. Porcher and 

 Morey state having discovered by Rontgen photography the presence 

 of a coffee spoon in the last portion of a dog's oesophagus and having 

 removed it by gastrotomy. Healing by primary intention. 



(e.) IMPACTION OP THE CEOP IN BIEDS. 



The crop is a diverticulum of the oesophagus, in which the food 

 is prepared for digestion as in the first compartments of the 

 ruminant's stomach. Impaction results from excessive distension 

 with dry foods, or with indigestible foreign bodies, and from com- 

 pression of the oesophagus in disease of the lungs. 



Symptoms comprise excessive fullness or distension of the crop, 

 which feels hard and firm, want of appetite, and sometimes discharge 

 of offensive fluid from the beak, which is usually held open. If 

 the condition persists for long or frequently recurs, the crop becomes 

 greatly dilated, the animals gradually waste, and may die. The 

 condition is seen in fowls, ducks, geese, and pigeons and by 

 recurrence becomes chronic. 



Treatment consists in massage. Attempts should be made to 

 empty the crop or to break down the hardened contents by pressure 

 and kneading. Ziirn recommends hydrochloric acid. If this proves 

 useless, as in distension with foreign bodies like sand and stones, 

 the crop must be emptied by operation, which is well sustained by 

 most birds. After removing the feathers, the crop is divided in 

 the long direction of the neck far enough to allow of the finger 

 entering and the contents being withdrawn. The Avound is cleansed 

 and sutured, and generally heals by first intention. According to 

 Ziirn pigeons are not good subjects for operation, especially during 

 breeding, the mucous membrane of the crop being swollen and very 

 rich in blood-vessels. 



