366 CHRONIC CATARRH OF THE GUTTURAL POUCHES. 



a piece of bone derived from a fractured hyoid. Hering and 

 Hahn discovered in a glandered horse cicatrices, small abscesses and 

 ulcers in the mucous membrane of the sac ; the latter was distended 

 with a muco-purulent collection. Hallander found a sarcoma in the 

 guttural pouch. It had extended into the spinal canal and caused 

 hemiplegia. The pouch showed signs of catarrh. 



Symptoms. (1) The nasal discharge is one-sided, intermittent, 

 muco-purulent, generally without unpleasant smell, occasionally 

 appears for a time in considerable quantity, and may then entirely 

 disappear. Pressure on the guttural pouch, as in placing the bit in 

 position or lowering the head, increases the discharge. 



(2) The swelling is sometimes slight, sometimes well marked. In 

 one horse, whose right sac held more than 2 pounds of concretions, 

 scarcely any swelling could be observed from the outside. In another, 

 swelling occurred in a marked degree in the parotid region, especially 

 when the head was lowered. Occasionally the swelling of one side 

 is also appreciable on the other, and may give the impression that 

 both pouches are diseased. The greater the swelling, the more 

 marked its fluctuating character. Entrance of air into the 

 diseased pouch causes a churning sound when the horse moves 

 its head, and percussion reveals pretty clearly the division between 

 fluid and air. Should the horse feed from the ground, or be ridden 

 or driven, a portion of the contents of the sac is discharged, and the 

 swelling visibly diminishes. 



(3) Severe distension compresses the larynx, trachea, and pharynx, 

 and produces difficulty in breathing and swallowing. Inspiration 

 soon begins to produce a rough sound, and at a later stage expira- 

 tion becomes loud. The seeming contradiction between clinical 

 observations and Gerlach's experiments, in which filling the sac 

 with a mass of plaster produced no difficulty in breathing, is 

 explained by the fact that the dyspnoea is not produced by the 

 filling of the sac, but by the distension pressing on the larynx and 

 trachea. Filling the pouch with large quantities of fluid or gas is 

 usually accompanied by dyspnoea, whilst filling with hard materials, 

 such as chrondroids, produces no such result. Experiment confirms 

 this statement, which also agrees with most of the cases reported. 



(4) In severe distension the animal holds the head towards the sound 

 side — a condition particularly pronounced when the horse is ridden. 



This affection is sometimes mistaken for disease of the parotid or 

 subparotideal lymph glands, in which the swelling is, however, less 

 sharply defined. Ulcerative processes in the pharynx and empyema 

 of the facial sinuses produce similar discharges. 



