I 



NASAL GLEET. 375 



gallop or otherwise severely try the animal's wind. Even if he 

 does so, he cannot get beyond the fact that the horse is unsound 

 in its organs of breathing ; temporarily or permanently he cannot 

 say, unless roaring (p. 380) is present. An examination of the 

 state of the glands between the angles of the lower jaw, will not 

 help him much, because they may be more swollen in ordinary cold 

 in the head than in nasal gleet. As a great rule, however, the dis- 

 charge of the former issues from both nostrils, although it may 

 come more from one than the other; but that of the latter is almost 

 always confined to one, namely, the left, as I have already ob- 

 served. In catarrh, the discharge is rarely offensive in odour, and 

 the eyes, which are not necessarily implicated in nasal gleet, are 

 generally more or less inflamed. In the former disease, the mucous 

 membrane of the nostrils will be red ; but in the latter, it will often 

 be of a leaden or yellowish hue indicative of general weakness. 



Having satisfied ourselves that glanders is not present, we should search for 

 pus in the sinuses (beginning with the superior maxillary sinus as the most 

 likely one) by boring into them with an ordinary gimlet, on withdrawing 

 which, if pus be present, some of it will be found in the groove of the instru- 

 ment. In case of doubt, this operation should not he neglected ; for it is 

 generally conclusive and is easy to perform. Before exploring with the gimlet. 

 we might test for the presence of pus by tapping the part from the outside 

 with the finger. If it emits an abnormally dull sound — a fact which we may 

 test by repeating the percussion on the other side — we shall have reason to 

 think that our suspicions are confirmed. This method, however, does not 

 always give reliable results. 



CAUSES. — Although the causes of many oases of nasal gleet are 

 obscure, I think we may number among them : injury to the bones 

 of the face, as might occur from a blow or fall ; cold in the head ; 

 and diseased teeth. With respect to cold in the head, we can 

 easily see that if the inflammation of the mucous membrane of the 

 air-passages of the head, extends to that of the sinuses ; the dis- 

 eased discharge may be retained in these cavities, owing to the 

 small size of the passages which drain them into the nose, in which 

 case, a collection of pus would be the probable consequence. As 

 regards diseased teeth, we should bear in mind that the fangs 

 of the fourth, fifth, and sixth molars penetrate into the superior 

 maxillary sinus; and, consequently, disease in them might, not 

 unlikely, set up inflammation in the mucous membrane of that 

 sinus. Also, the fourth, molar is more liable to decay than any 

 of the others. 'It is thought by some authorities that the en- 

 trance of foreign bodies, such as particles of food, into the sinuses, 

 may give rise to nasal gleet. Against this supposition, Colin 

 tells us, in his '' Physiologie Comparee," that experiments on the 

 living animal prove that the tension of the air in the sinuses 

 of the head is increased during expiration, and is diminished 



