12 CLINICAL VETERINARY MEDICINE AND SURGERY, 



antiseptic solution and plugging the trephine opening. At the end of 

 a week the discharge by the trephine wound and left nostril had 

 already diminished, and afterwards continued gradually to lessen. 

 During the fourth week we ceased plugging the wound. Some days 

 later the animal returned home. 



As a rule, the troublesome cases are those where the mucous mem- 

 brane is thickened, shows exuberant granulations, or is affected with 

 polypoid degeneration. Sometimes persistence of the discharge is due 

 to the anatomical formation of the inferior maxillary sinus, to the fact 

 of its being prolonged an inch or so below the extremity of the 

 zygomatic ridge, — that is, beyond the point where this sinus is usually 

 trephined ; a quantity of pus remains in the lower part of the cavity, 

 and keeps up inflammation of the mucous membrane. It also hap- 

 pens at times that this sinus is very large and deep, allowing the puru- 

 lent fluid to accumulate and keep up exudation from the mucous 

 membrane. In cases of this nature it is advantageous to make an 

 opening through the internal wall of the sinus, level with the inferior 

 meatus of the nasal cavity as above indicated. With a small surgical 

 stock and bit the operation is easy. Care is required, however, to 

 make the opening level with the meatus, and not with the internal 

 portion of the large submaxillary sinus ; if placed too low the instru- 

 ment penetrates into the palatine plate of the superior maxilla. 



The need for plugging the trephine openings, to prevent their 

 closing up before suppuration ceases, is unfavourable to cure, because 

 during the interval between the times of changing the dressing pus is 

 retained in the sinus. This may be prevented by fixing in the openings 

 closely fitting tubes of wood, provided with a little handle on the 

 external surface. With the same object, metal or gutta-percha cannulse 

 may be employed. 



Before concluding, I must refer to one of our patients which 

 died. An entire cart-horse, twelve years old, was brought here 

 towards the middle of March, i8g6. He had long had a discharge 

 from the right nostril, which finally became so offensive that the 

 driver refused to take him out. The animal was in a bad state, 

 thin and exhausted ; he lay down as soon as he entered his box. A 

 purulent offensive discharge escaped from the right nostril. There 

 was no deformity of the sinus, and the submaxillary glands were little 

 enlarged. On examining the mouth it was seen that the horse 

 " pouched " his food on both sides, especially on the right. The 

 fourth right lower molar projected beyond the others nearly half an 

 inch. Having inserted a gag, we discovered that the corresponding 



