138 DISEASES OF THE ESOPHAGUS 



glands resulting in fermentation or decomposition of the crop 

 contents which irritate the mucous membrane often pro- 

 ducing a severe catarrhal inflammation. Eating indigestible 

 or decomposed substances (feathers, putrid meat, etc.) often 

 produces catarrh of the crop. 



Poisons (arsenic, phosphorous, salt, etc.), when taken acci- 

 dentally or given intentionally, often produce a very severe 

 form of the disease. The presence of parasites (Dispharagus 

 nasutus, etc.) in the crop will in most cases produce a catarrhal 

 inflammation, the severity of which depends upon the num- 

 ber present. In pigeons fermentation of an overabundant 

 secretion after the loss of the young will produce a serious 

 catarrhal inflammation of the crop and other parts of the 

 digestive tract. Crop catarrh also occurs during the course 

 of some diseases (diphtheria, thrush, cholera). 



Symptoms.— Distention of the crop is at first the most 

 noticeable symptom. On palpation the crop will be found 

 to be soft and fluctuating, due to an accumulation of liquid, 

 gaseous and solid food material. Loss of appetite, eructations 

 of gases, sometimes retching and vomiting are symptoms. 

 By pressure upon the crop the contents will be expelled via 

 mouth, emitting a very offensive odor. The birds may die 

 from exhaustion. 



Diagnosis.— This is determined quite accurately by a care- 

 ful examination of the crop and the character and condition 

 of the contents. 



Prognosis.— When not a symptom or complication of 

 some other disease (cholera, thrush, etc.), the prognosis is 

 usually considered favorable and the majority respond readily 

 to treatment. When a large number of a flock is affected, 

 indicating a severe catarrhal inflammation, the prognosis is 

 less favorable owing to the difficulty in applying prompt 

 remedial measures. Repeated return of the condition often 

 produces the so-called hanging crop or dilation. 



Treatment.— Hygienic.— The birds should be provided with 

 a clean, dry place free from extremes in temperature. 



Dietetic.— In mild cases where the appetite is not entirely 

 lost, solid food should be withheld for a day or so, only a 

 small quantity of liquids being allowed. 



