550 A GRASS COLD. 



causing a horse to eat oats, hay, or, better still, a turnip on 

 the ground. The shaking of the head as the turnip is being 

 nibbled, leads to a free escape of fetid pus. I have found 

 that the attendants on a horse thus affected have usually 

 spoken to me of pus dropping into the pail as the animal 

 drank. When horses are at grass the discharge is regular, 

 but at no time so abundant as when the horse is kept in the 

 stable and occasionally worked. This depends on the regular 

 escape of the pus when a horse is constantly feeding off the 

 ground, and in mild cases I have found this sufficient to 

 effect a cure. I attribute to this that the disease has been 

 termed " a grass cold/' and the advice often given by some 

 veterinary surgeons in Scotland, when failing to cure a 

 chronic nasal discharge, that it will pass off at spring time, 

 when the animal is turned out for a month or two. If the 

 relation of the Eustachian opening to the guttural pouch, 

 pharynx, and nasal chamber is noticed in Fig. 124, page 451 

 of this work, it will be readily understood how the pus only 

 escapes when the animal's head is depressed. 



A horse with much accumulation of pus in the guttural 

 pouch, sometimes roars, and has a thick gummy neck. He 

 does not thrive well, and is often looked upon suspiciously, 

 as probably affected with glanders. 



Treatment. If feeding a horse from the ground for some 

 time, or a run at grass does not cure the discharge, the gut- 

 tural pouch must be opened. Giinther has devised an in- 

 strument to wash out the guttural pouch (Fig. 141), but I 

 have not found it of much service in practice, and prefer 

 performing hyovertebrotomy at once. 



The instruments needed for this operation consist in scis- 

 sors, scalpel, forceps, iron staff (see Fig. 140), and tape. A 

 syringe may be used to wash the pouch as thoroughly as pos- 

 sible whilst performing the operation. 



