CHAPTER 37 OTITIS EXTERNA, MEDIA, AND INTERNA 543
SIGNALMENT/HISTORY
Breed Predilections
Pendulous-eared dogs: spaniels, retrievers, and hounds.
Hirsute canals: terriers and poodles.
Stenotic canals: Chinese shar pei.
Primary secretory otitis media: cavalier King Charles spaniel and boxer.
Historical Findings
Pain (shying from touching of the head or refusing to open the mouth).
Head shaking (if both ear canals are severely affected, the patient may not shake the
head as vigorously as expected due to pain).
Scratching at the pinnae.
Malodor.
Peripheral vestibular deficits.
Loss of hearing acuity.
Facial nerve deficits and/or Horner’s syndrome.
Unilateral (i.e., foreign body, polyp, tumor) versus bilateral (i.e., hypersensitivity,
endocrinopathy).
Otitis externa was reported as being more disturbing to clients than to patients in one
study.
Risk Factors
Abnormal or breed-related conformation of the external canal (e.g., stenosis, hir-
sutism, and pendulous pinnae) restricts proper airflow into the canal.
Excessive moisture (e.g., swimming, environmental humidity, or frequent cleanings)
can lead to infection; overzealous client compliance with recommendations for ear
cleanings and/or use of inappropriate solutions.Topical drug reaction and irritation or trauma from abrasive cleaning techniques.
Underlying systemic diseases producing abnormalities in the microenvironment of
the ear canal environment and in the immune response.
Otitis media is a frequent sequela of chronic otitis externa.
Nasopharyngeal polyps, and inner, middle, or external ear canal neoplasia.
Inhalant anesthesia may change middle ear pressure.
CLINICAL FEATURES
Otitis Externa
Deafness.
Erythroceruminous: ceruminous discharge with erythema; often associated with sec-
ondaryMalasseziaor staphylococcal infection; pruritic (Figure 37.3).