In pigs, fibroma is met with in the walls of the gullet (Raveski) and in dogs fibroma, papilloma, and the tumors of spiroptera.
Symptoms. The coccidia and spiroptera usually cause few symptoms or none, but neoplasms usually develop symptoms of obstruction, dysphagia, eructation, vomiting, and all the indications of choking according to their seat. These do not come on suddenly and recover as in simple choking, but even though there may be periodic obstructions, spasms and paroxysms, there is a slow, progressive advance as the neoplasms increase. Stertorous or mucous breathing, cough, dyspnœa and fœtid exhalations are common, the symptoms may be aggravated when the head is bent, and the tumor may even be felt on palpation of the throat or left jugular furrow. In ruminants tympany occurs after feeding.
Treatment is surgical and consists in the removal of the tumors by incision and ecraseur or otherwise. Thoracic œsophagean tumors are usually inoperable.
IMPACTION OF THE CROP. INGLUVIAL INDIGESTION.
Gallinaceæ and Palmipeds. Causes; Overfeeding after privation; fermentation; lack of water; green food in geese and chickens; food containing paralyzing element. Symptoms; dull; motionless; erect plumes; drooping wings and head; gapes; ejects liquid from bill; firm cervical swelling. Treatment; manipulation; incision; surgical precautions. Convalescent feeding.
The cervical dilatation of the œsophagus known as the crop is well developed in all granivorous birds, (Gallinaceæ, etc.;) and like the macerating cavities of the ox (first two stomachs) is subject to overdistension and paralysis. In the palmipeds (ducks, geese) there is no distinct crop but in its place the cervical portion of the gullet has a fusiform dilatation, and under given conditions this may be also the seat of impaction.
Causes. The impaction may result from overfeeding when the bird has been starved, or when it suddenly gains access to food of a specially appetizing kind and to which it has been unaccustomed. The crop like every other hollow viscus is rendered paretic by overdistension. Then the food undergoes fermentation still further distending the cavity, affecting the brain by reflex action, and paralyzing the vagus and its peripheral branches in the lungs, heart, stomach, liver, intestines, etc. When the food is dry as in the case of beans, peas, bran, farinas, it may be a simple firm impaction which the muscular walls of the crop are unable to break up or move onward. When green food is taken there is often superadded the additional evil of active fermentation from the great number and activity of the bacterial ferments contained in it and the soft aqueous fermentescible nature of the food (See tympany in ruminants). Dupont states that young geese led out to fresh spring grass may lose two-thirds of their number in a few hours from such overloading and that some species of Carex and cynodon dactylon are particularly injurious. Chickens also gorge the crop with clover, etc. In all such cases, plants that contain a paralyzing principle like lolium temulentum, ripening lolium perenne, chick vetch, etc., are to be specially dreaded. (See Trichosoma Contortum).
Symptoms. There are first dullness and sluggish movements, followed by indisposition to move, the bird standing in one place with ruffled feathers and drooping wings, and at intervals, projecting the head forward with open beak and in some cases a little liquid is rejected. If the bird is now caught and examined the crop is found to be firmly distended, and more or less compressible or indentable according to the nature of the food impacted. In most cases and especially if the food has been green or aqueous, there is a certain resiliency from the presence of gas outside the solid impacted mass.
Treatment. This must be in the line of seconding the physiological efforts of regurgitation which is a normal and common act in birds. The duck which has gulped a mouse half-way down the cervical part of the œsophagus will readily disgorge it when he finds it impossible to pass it further. The carnivorous birds often reject by vomiting the indigestible debris such as feathers and bones, after all the more soluble parts have been disposed of in the stomach. The pigeon even feeds its young by disgorging into their open bills, the semi-digested food and milk from its crop. Following these indications we must break up the contents of the crop by manipulation and force them in small masses upward into the bill and downward to the proventriculus. The rejection by the bill may be further stimulated by introducing the finger into the fauces to rouse the reflex active emesis. Usually the crop can be quickly and satisfactorily emptied in this way.
When this proves impossible there remains the operation of direct incision through the walls of the crop and the evacuation of its contents. This can be done by a pocket knife or even a pair of scissors. The crop is punctured in its lower part and the incision is continued upward as far as may be necessary to allow the escape of the contents. Usually half an inch will suffice. Then the crop is squeezed so as to press the contents through this opening and it is emptied by a process of enucleation. If the contents are fibrous it may be necessary to employ forceps to dislodge the material. The empty crop may be washed out with tepid water, any food attached to the raw edges of the wound must be removed and the skin stitched accurately together. The wound rarely fails to heal by first intention. To avoid stretching it, the food for a day or two should be restricted to milk, gruels, or a little soft mash.