76 Veteritiary Medicine. 



dullness and lack of energy, low carriage of the head, unsteadi- 

 ness of gait, lack of lustre in the eye, pupils dilated, semi-closed 

 eyelids, pendent lips, a tendency to lean on the stall or hang on 

 the harness, and though the animal may stagger and fall, there is 

 not the abrupt transition from life and energy to the active excite- 

 ment and uncontrollable movements. The same remarks apply in 

 a measure to narcotic vertigo. 



With optic vertigo, the attendant conditions will help to a 

 diagnosis. The animal has come from darkness to full sunshine ; 

 there is the white, icy or snowy reflection everywhere which the 

 animal was facing when attacked, or the glistening lake or river, 

 the overdraw check rein, or the blind with perhaps a shining inner 

 surface. The pupil is closed, ,and the eye is rolled back or oscil- 

 lates in one direction or another. The symptoms are checked by 

 covering the eyes or removing the subject into a dark building or 

 even into the shade of a tree or shed. 



With aural vertigo there may be similar rolling of the eyes, 

 without the pupillary closure, the ear may be drawn down or 

 back, and the shaking or jerking of the head is likely to be a 

 marked feature. If there is more motion of one ear than the 

 other, if the head is jerked to the one side, if there is a measure 

 of deafness in the one ear (to be ascertained rather in the inter- 

 vals between attacks), if there is disease of the pharynx, the Eu- 

 stachian tube or pouch, or swelling about the root of the ear, if 

 there is wax, scurf, or acarus in the ear, if the animal rubs it fre- 

 quently, aural vertigo may be suspected. 



Nasal vertigo. Those forms in which the head is jerked hor- 

 i-zontally, vertically, or diagonally, the animal pressing against its 

 mate or the pole, or outward in the harness, and getting out of its 

 track, even if it should stop short of falling, and which appear 

 only during work, or are aggravated by exertion, have been 

 attributed to lesions of the ear (Fleming), but in some cases they 

 can be warded off by wearing a net over the nostril, and can be 

 entirely stopped by complete transverse section of the pes anse- 

 rina, so that in a certain number at least they must be accounted 

 nasal. These are not usually attended by sneezing. The simple 

 expedient of driving with a rather close net over the nostril may 

 enable one to diagnose many of the purely nasal forms. 



Plethoric vertigo may be suspected when the attack comes on 



