202 KENNEL DISEASES. 
two tablespoonfuls to each half a pint of water; one-half of which quantity will 
be quite sufficient for one ear. 
Manifestly if the general health seems to be impaired, tonics and a generous 
diet are indicated. 
If a case resists treatment for several months without improvement it may 
be accepted that some structural change has occurred in the ear which makes a 
cure quite doubtful. Then, if the dog is not of much value, it will be advisable 
to sacrifice him, although he might live for several years and otherwise seem fairly 
well. 
OTITIS INTERNA. 
As stated in the opening section, the drum membrane divides the external 
from the middle ear; and although inflammation of the latter should properly be 
termed otitis media, and inflammation of the deeper parts otitis interna, it is 
quite sufficient for all purposes to combine inflammations of the middle and inter- 
nal ear under one head — otitis interna. 
Inflammations sometime originate in the cells, canals and structures that 
constitute the inner ear; but, as a rule, to which exceptions are comparatively 
rare, they first occur in the middle ear and extend inward. They also extend 
outwardly, in the opposite direction, and involve the drum membrane and 
external ear. Such inflammations may be confined to the mucous membrane 
that lines the middle ear, to the membrane covering the small bones, or even 
the bones themselves, though all these may become affected by them. 
The usual causes of otitis interna are exposure to cold, shock, such as may 
result from plunging into icy water, from remaining too long in cold water, and 
from injuries and blows in the region of the ears. It may follow and be a part 
of an inflammation that started in the external ear, otitis externa, and broke 
through the drum membrane; but this accident is far from common. Certain 
constitutional conditions and disturbances, which do not directly cause this 
affection, at least favor its occurrence. For instance, a dog whose blood is 
poor and his system debilitated, falls a victim to otitis interna much sooner 
than one in good health. 
In some cases of inflammation of the ear it is not possible for non-profes- 
sionals to determine whether the same is external or internal otitis, though the 
existing disease has been on for weeks or months; but, as a rule, in acute cases, 
in which the inflammation commenced within a short time, it is easy to discrimi- 
nate between the two forms, because the symptoms of internal otitis are much 
more severe than those of the external. 
Otitis interna generally commences quite suddenly, usually attacking one ear, 
and is characterized by pain that is sometimes so severe that it is almost mad- 
