Diagnostic examinations are markedly improved by using rigid endoscopy in the ear, nasal cavity, and urinary tract. This article
presents the procedure, equipment, indications, and examples of abnormalities of rigid endoscopy in these areas. Textbooks,
"hands-on" courses, and in-hospital training are methods for learning about these techniques and their applications. In addition
to improving diagnostics, endoscopy can also be used for therapy in these three body areas. Otoscopy Definition and Tools 
Fig. 1: (A, B) Video otoscopy used to examine a cats ear during anesthesia. Examination is carried out before and after thorough
cleaning. Note that the operator is looking at the monitor, which is opposite the ear from the operator. Swabs for cytology
and culture, if indicated, are done before cleaning. A deep culture should be obtained if the tympanic membrane is ruptured
or if there is obvious otitis media. A short movie of the ear mites seen in this cat can be downloaded from the website, www.vet.uga.edu/mis.
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Video otoscopy uses video cameras and endoscopic lighting combined with an otoscope to examine the external and middle ear.
Video otoscopy is a vast improvement over traditional otoscopy because the image is magnified and projected on a monitor compared
with visualizing through a small otoscope loop (Fig. 1). Flushing with fluids during anesthesia concurrently clears the field
of view. Veterinarians can markedly improve their examination of the ear and, equally important, the client can gain an appreciation
of the disease process. Practitioners using video otoscopy strongly vouch for the subsequent improvement in client compliance
and patient's ear care.
Fig. 2: An otoscopy cone used with an endoscopic camera and light source. Either a suction irrigation machine (Vet Pump 2)
with a 5 Fr red rubber urinary catheter or a "Y" shaped stopcock attachment with integrated operating channel can be connected
to the infusion channel. During anesthesia, video otoscopy is commonly done with a rigid endoscope, such as a 2.7-mm diameter,
18-cm long scope with either an arthroscopy or cystoscopy sheath (Karl Storz Veterinary Endoscopy, Goleta, California). The
cystoscope has an inflow and efflux port in addition to an operating channel, whereas the arthroscope sheath is smaller and
only has an inflow port. The cystoscope has a rounded, more benign tip than the arthroscope. Smaller rigid scopes can also
be used for the ear.
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Instrumentation for video otoscopy requires the standard camera, light, image processor, and digital capture system in a standard
endoscopy tower (Karl Storz Veterinary Endoscopy, Goleta, California). The camera and light cable are connected to a video
otoscopy cone and small diameter endoscopes (Fig. 2). Only the video otoscope cone is required for awake and sedated examinations
in the outpatient arena. Air is the optical medium in wakeful patients.
Fig. 3: This 5-year-old German shepherd has a history of skin disease. Both ears had a 4-month history of mucopurulent discharge
and pain, as reflected by his ear carriage (A). The ears had previously transiently improved with cleaning and prednisolone.
The ears are severely inflamed and erythematous, typical of an allergic response (B).
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Smaller endoscopes and otoscopy cones can be used while infusing fluid in anesthetized patients. Smaller diameters used include
1.9-mm and 2.7-mm endoscopes encased in cystoscope sheaths. These endoscopes have a 30° viewing angle, and the sheaths have
an operating channel. Arthroscope sheaths also work well and provide an excellent avenue for irrigation; however, they do
not have an instrument channel. Ancillary equipment includes flushing catheters, biopsy forceps, foreign body removal forceps,
curettes, ear loops, mosquito forceps, alligator forceps, and suction.
Indications and Case Selection 
Fig. 4: Video-otoscopic image of the left ear of a 5-year-old neutered male cat. The left ear had had a bloody discharge,
first observed 1 year previously. Biopsy was an inflammatory polyp. Treatment requires removal of the polyp from both the
bulla and eutaschian tube. This is done either by ventral bulla osteotomy or by otoscopy, in which the septum between the
cranial lateral and larger ventral medial tympanic bulla compartment is perforated sufficient to debride the medial compartment.
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Ear diseases are extremely common problems in general veterinary practice.1,2 Dermatologists use the ear as a sentinel for generalized skin diseases, for example, dietary-based allergic dermatitis. Acute
signs of otitis externa include pinnal and otic hyperemia, edema, and excoriation (Fig. 3). Chronicity leads to hyperplasia
and mineralization of the ear canal. Most patients have an abundance of malodorous discharge and pruritus, as evidenced by
head shaking and pain. A thorough dermatologic examination is essential, and the ear should be cleaned as the first step in
treatment. Most dogs and cats have otitis externa, but otitis media must be ruled out for effective topical treatment. Neurologic
and otoscopic examinations are helpful in diagnosing otitis media. Indications for video otoscopy are (1) clinical signs of
ear disease, (2) otic odor, discharge, or pain, (3) older dogs presenting for geriatric examination, (4) breeds commonly affected
by ear disease, and (5) chronic skin disease.1,2 Video otoscopy done in the outpatient room is a cursory examination at best and should be restricted to evaluation of a healthy
ear with no clinical signs or to identification of problems requiring more intensive examination. When the ear is inflamed,
painful, or filled with purulent material, anesthesia is required to perform a thorough cleaning and examination. The combination
of anesthesia, improved video images, and irrigation through the scope improves visualization of the ear canal and tympanic
membrane, and it is ideal for diagnosing otitis media. Skull radiographs are helpful, but limited in their diagnostic sensitivity
for middle ear disease. Computed tomography (CT) and magnetic resonance imagining (MRI) are useful for examining the tympanic
bulla but are expensive compared with video otoscopy. Undiagnosed and incompletely managed middle ear disease is a common
cause of persistent otitis externa. In addition, failure to rid the ear of exudate makes it nearly impossible to appropriately
medicate the external ear.
Typical Abnormalities 
Fig. 5: Video-otoscopic view of the left ear of a 4-year-old female spayed mixed dog with recurrent left side otitis externa.
The biopsy diagnosis was a benign papilloma with moderate monocytic to neutrophilic perivascular dermatitis. This mass should
be surgically resected with selection of the surgical procedure based on mass location and size. Resection may be local or
as extensive as total ear canal ablation.
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The most frequent abnormalities are an abundance of malodorous discharge and inflammation. An ear swab for cytologic examination
for yeast and bacteria should be taken before ear cleaning, and cultures are easily obtained. The ear canal may be narrow
as a result of congenital or acquired disease and may be obstructed by hyperplasia. Other findings include ear mites, mass
lesions, and foreign bodies. Masses should be sampled for histologic examination. Multiple causes of ear diseases include
infection (bacteria, yeast, or fungal), foreign bodies (foxtails, plant material, and exudate), allergy (atopy, food, or contact),
endocrinopathies (hypothyroidism or sex hormone imbalance), seborrhea (primary or secondary), conformation (stenotic, hypertrichosis),
immune-mediated diseases (pemphigus or lupus), benign masses (polyps or hyperplasia), and neoplasia (ceruminous gland adenocarcinoma,
squamous cell carcinoma). Representative cases of the above lesions are presented in Figs. 4–9.
Patient Management After Endoscopy 
Fig. 6: Video-otoscopic view of the left ear of a 10-year-old male cocker spaniel. The histologic diagnosis was a well-differentiated
ceruminous adenocarcinoma. A fine-needle aspirate from the mandibular lymph node was negative for cancer cells. Treatment
was believed to be successful after total ear-canal ablation with a lateral bulla osteotomy, when the surgical margins were
negative for cancer.
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In the first few hours, postoperative pain is managed by mild oral analgesics, such as tramadol, which is often dispensed
at discharge. Many patients require corticosteroids as a part of their treatment, or nonsteroid analgesic drugs can be used.3 Indications for surgery are persistent otitis that fails to respond or does not appear to be likely to recover with medical
treatment. Otitis externa and otitis media require persistent medical management by the veterinarian and client. Once ear
disease recurs, the ear must be regularly examined by video otoscopy. It aids in managing middle ear disease by lavage and
cleansing of the middle ear through the ruptured tympanic membrane. Failure to maintain an acceptable external canal lumen
is an indication for ear surgery. Having worked in a variety of practices as a referral general surgeon, the author has observed
that the effectiveness of medical treatment has markedly altered the number of patients operated. Aggressive and persistent
video otoscopic treatment can markedly reduce the requirement for end-stage ear surgery.
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