Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

216 •DOG OWNER’S HOME VETERINARY HANDBOOK
Small tumors tend to be benign. Large tumors are usually malignant and
invasive. Cocker Spaniels seem to be predisposed to these tumors.
Treatment: Surgical removal is the treatment of choice. Surgery, combined
with radiation therapy, is recommended for invasive tumors.
The Middle Ear
OTITIS MEDIA (MIDDLE EAR INFECTION)
Otitis media is an infection of the eardrum and the cavity of the middle ear,
including the three bony ossicles. Most cases are caused by an outer ear infection
that involves the eardrum and then progresses to the middle ear. In fact,
about 50 percent of cases of chronic external otitis are associated with otitis
media. Bacteria can also gain entrance to the middle ear through the opening
of the auditory tube that connects the middle ear to the nasopharynx.
Occasionally, the infection is blood-borne.
The early signs of otitis media are the same as those of external otitis (page
212). However, as the middle ear becomes infected the pain increases dramatically.
The dog often tilts her head down on the affected side, holds it as still
as possible, and exhibits increased pain sensitivity when her head is touched
or her mouth is opened. Hearing can
be affected, but the loss may not be
noticed unless both ears are involved.
An otoscopic examination performed
after the dog has been sedated
or anesthetized reveals a bulging
eardrum. If the drum is ruptured, pus
may be seen draining from the middle
ear. X-rays occasionally show fluid or
inflammatory tissue in the middle ear
cavity.
Injury to a branch of the facial
nerve that crosses the eardrum causes
drooping of the upper lip and ear on
the affected side. Another sign of
facial nerve injury is Homer’s syndrome,
a symptom complex of the eye
that consists of a small pupil, drooping
upper eyelid, protrusion of the nicti-
Horner’s syndrome can be caused by
otitis media. This dog shows the protruding
third eyelid and drooping upper
eyelid characteristic of Horner’s.
tating membrane, and retraction of
the eyeball into the orbit.
Treatment: This involves thoroughly
cleansing and flushing the
ear, as described for external otitis