372 CHRONIC CATARRH OF THE GUTTURAL POUCHES. 



17th that the horse showed no dyspnooa, even on movement, treatment 

 was discontinued, and the animal sent to grass. In December the horse 

 was quite capable of work ; the operative wound was not then closed, 

 though it had become smoothed off. The discharge was slight, and the 

 pouch markedly smaller. 



This case shows how obstinate the disease may be. Such diffi- 

 culties are to be expected. Where the condition has existed for a 

 long time, and the sac has been much dilated, it cannot, owing to 

 its connection with neighbouring parts, readily resume its normal 

 volume. Possibly dilatation of the opening of the Eustachian tube 

 produced by the discharge also forms an obstacle to healing. 



Thomassen's case of hydrops of the pouch also showed swelling, 

 slight respiratory dyspnoea, and want of appetite. An experimental 

 opening was made, and four pints of amber-coloured serum allowed 

 to escape. A drainage-tube was inserted, and recovery occurred in 

 three months. 



Cadiot and Dollar describe a case of chronic pharyngitis and 

 catarrh of the guttural pouches cured by double hyovertebrotomy. 

 The animal was thin, had difficulty in swallowing, showed a muco- 

 purulent discharge mixed with fragments of food from both nostrils, 

 and occasionally suffered from violent attacks of coughing. Part of 

 the drinking water returned by the nostrils. Both guttural pouches 

 were opened and daily irrigated with antiseptic solutions for a period 

 of three weeks. Recovery was almost complete in a month. 

 (" Clinical Veterinary Medicine and Surgery.") 



(6.) TYMPANITES OF THE GUTTURAL POUCH. 



The significance of the guttural pouches has been variously interpreted. 

 Franc k viewed them as safety valves to control the air pressure in the 

 middle ear, and prevent excessive tension of the tympanum by alteration 

 of pressure. The suggestion that they are involved in voice production. 

 or that the respiratory air is warmed during its stay in them, seems 

 improbable. 



Perosino discovered, by experiment, that during expiration the pouches 

 were dilated, and that during inspiration they collapsed again. He intro- 

 duced a tube containing alcohol into the pouch through a cannula, and 

 noticed that the fluid rose during expiration and fell during inspiration. 

 The phenomenon was exaggerated during violent respiration. Perosino 

 therefore considered the guttural pouches were intended to moderate the 

 stream of inspiratory air during violent exertion. Prince, on the other 

 hand, supported the view first suggested by Prange, viz., that the guttural 

 pouches serve to assist movements of the head by acting as elastic cushions. 

 Perosino states that, in animals suffocated by stopping up the nostrils, 

 the guttural pouches are enormously dilated. 



