CANINE INFLAMMATORY MASTOID DISEASE. 
353 
npactions of foreign bodies, or hardened secretions, in the audi- 
ary canal or upon the drum membrane, provoking' suppuration 
nd violent otic inflammation; it is nature’s remedy to remove the 
vil, and if unsuccessful is prone to result in mastoid disease, 
’anaceas, lotions, caustics, and nostrums innumerable adminis- 
jred for simple otic inflammations and otorrhoea , without knowl- 
dge of cause, are responsible for more injuries in canines than the 
lity will ever know, since the well trained animal obeys instincti¬ 
vely, and by eye oftener than through aural perception. A dog 
f ordinary intelligence that will not, during a moment of quiet, 
uestion some unusual concealed sound, as the ticking of a watch 
r vibration of a tuning fork, at a distance of four or five feet if 
t eld in the same line and plane with the ear, is most probably de- 
cient in hearing. It is generally believed that all Pomeranian 
ogs are deaf. This is not true, save during puppyhood ; as a race 
leyare extremely slow in development of pneumatic cells, which 
ot infrequently delay their appearance until the seventh, eighth, 
r ninth month. 
As already intimated, any form of otic inflammation, if unre¬ 
eved, either through natural or artificial causes, must invariably 
roceed to mastoid disease. Primary inflammation of the mastoid 
ntrum and pneumatic cells, save as the result of direct injury, is 
nknown. The lining of the mastoid cavities is but a prolifera- 
on of the mucous membrane of the middle ear, hence the sym- 
athy that must exist during inflammation of that cavity. 
Mastoid disease manifests itself in three ways : 1. As perios- 
tis of the outer surface of the bone. 2. Congestion and inflam- 
lation of the mucous lining of autrum and cells, commonly both. 
. Caries and necrosis involving the middle and internal ear, 
allowed, perhaps, by meningitis , cerebral abscess , thrombosis of 
tteral sinus, and pyaemia. 
The first may arise from acute inflammation of the middle ear 
^d consecutive inflammation of the external auditory canal. The 
)cond and third are the result of direct extension of an otitis 
xedia to the autrum and spaces of the mastoid. Inflammation 
i any case may arise at any time during life and the continuance 
f purulent accumulations within the middle ear, and may appear 
