INFLAMMATION OF THE EXTERNAL AUDITORY MEATUS. 
Ill 
base of the cartilage produces an agreeable sensation, the animal leaning 
towards the operator, and holding the head on one side. A bubbling 
sound may perhaps be heard, owing to motion of the fluid contents of 
the ear. After some time the secretions become yellowish-brown, and 
excoriated spots appear in the depths of the meatus. In the deep form 
one meets with a purulent discharge (otorrhcea); granulations appear 
on the surface of the diseased meatus, and caries of the petrous temporal 
bone may ensue. Sometimes pus formation preponderates; sometimes 
formation of granulations. The latter may obliterate the external 
opening. Perforation of the tympanum and otitis media are rare. 
Whilst irritation disappears early in the chronic superficial form, the 
deep form is usually accompanied by greater pain. Frohner records 
vomiting in dogs, which he referred to irritation of the ramus aunculans 
of the vagus nerve. Implication of the middle ear or brain may pioduce 
epileptiform fits and other brain symptoms; but, considering the 
frequency of such ear diseases in dogs, these complications are seldom 
observed. Masch describes such a case in the horse, which showed a 
purulent discharge containing fragments of bone from the external ear. 
The horse was killed, and on post-mortem examination was found to be 
suffering from necrosis of the petrous temporal bone and an abscess 
under the dura mater. 
In order to view the largest possible portion of the meatus, the head is 
placed downwards, the cartilage grasped with both hands, and held in such 
a position as to direct the passage, which lies sideways, somewhat towards 
the front. The aural speculum is of no great value in dogs, as the tympanum 
is not visible. The resistance of the animal, moreover, interferes both with 
the insertion of the instrument and the examination. 
Prognosis. Acute otitis is readily curable, but chronic otitis externa is 
often extremely obstinate. In the superficial form care and perseverance 
will usually succeed, but the deep form is usually incurable; the more 
profuse the discharge of pus, the less the chance of recovery. 
The treatment of acute otitis can usually be effected by repeated 
cleansing of the meatus and the use of mild astringents. A small soft 
sponge fastened to a stick is dipped into lukewarm water or solution of 
acetate of lead, gently squeezed and inserted into the meatus. Slow rotary 
movements remove the secretion, when the meatus may be washed out 
with a solution of acetate of lead, care being taken to thoroughly remove 
all traces of fluid with a sponge. Excoriations can be painted with a 
2 per cent, solution of nitrate of silver. Where pain is excessive, 
lukewarm oil of henbane dropped into the ear often gives relief. The 
washing of the meatus must be repeated at least once a day, and 
continued until the discharge has completely disappeaied. 
In chronic superficial otitis the first requisite is careful cleaning of the 
meatus with lukewarm soap and water and an eai-sponge, followed by 
