548 DISCHAKGE FROM GUTTURAL POUCHES. 



Treatment consists in using Key's nasal tube daily, but if 

 the sinuses cannot be cleared that way, trephining must be 

 resorted to. 



The instruments necessary for this operation consist in a 

 pair of scissors, knife, and forceps, trephine, whalebone probe, 

 about six inches in length, or a seton needle, and tape. 



The horse being cast, is turned, so that the side of the head 

 to be trephined is uppermost. An imaginary line is then 

 drawn from one orbital arch to the other, and below this 

 line, midway between the margin of the orbit and the 

 mesian line of the head, the hair is clipped, and a crucial 

 incision is made. The skin is reflected back after separating 

 it thoroughly from the bone with the periosteum. The point 

 of the trephine is then implanted in the centre of the ex- 

 posed portion of the bone, and with a few sharp turns a cir- 

 cular piece of bone is removed. Another opening must be 

 made in the same way into the upper jaw above the zygoma. 

 The cavities are then washed out with tepid water, and a 

 seton is drawn through from the upper to the lower orifice; 

 the ends of the seton are tied together. The cavities must 

 be washed out daily, and an astringent lotion occasionally 

 used. The seton must be frequently changed, and this 

 simple operation is performed by cutting the old tape across 

 and fixing to one end a fresh piece. The old is then pulled 

 through, and it carries with it the new seton, which is tied 

 in its place. 



The constitutional treatment required is usually very 

 simple, but there are cases which need the same tonic course 

 as that adopted in simple nasal gleet. 



III. Accumulation of Pus in the Guttural Pouches. This 

 is the result of strangles or severe catarrh, and frequently 

 the discharge occurs into the pharynx, or through the skin 

 at the anole of the iavv. Suffocation has frequently occurred 



