Page 1437 - Cote clinical veterinary advisor dogs and cats 4th

Otitis Externa 729

Initial Database Advanced or Confirmatory Testing • Resolve infection with topical otic antimicro-
bial agents, and monitor response to therapy.
• Physical exam: to identify the underlying • Video otoscopy (p. 1144) allows greater • Prevent recurrence by diagnosing and manag-
VetBooks.ir In the dog, the most common causes are • Radiographic imaging: plain radiology, CT, ing the primary cause, perpetuating causes, Diseases and Disorders
visualization and detail resolution of the
dermatologic disease that triggered the otitis.
ear canal and tympanic membrane.
allergic diseases (e.g., cutaneous adverse food
and predisposing factors.
reaction, atopic dermatitis), and in the cat,
middle, and internal parts of the ear.
O. cynotis and nasopharyngeal polyps are and MRI are used to image the external, Mainstay of therapy for otitis externa is topical
otic therapy, with the choice of topical otic
more common primary causes of otitis than Abnormal findings indicate otitis media, medication based on
allergies. but normal radiographic findings do not • Results of otic cytology are used to choose
• Otic exam: to evaluate the vertical and hori- rule out otitis media. the active ingredient in the topical otic
zontal ear canal for evidence of hyperplasia, • Ear flush under anesthesia: to completely medication.
stenosis, and ulceration, as well as to evaluate clean the external ear canal when further ○ Options for bacterial otitis externa
the amount, consistency, and color of the otic exam is needed include aminoglycosides, polymyxin B,
exudate. If possible, the tympanic membrane • Audiologic testing: brainstem auditory florfenicol, silver sulfadiazine, tris-EDTA,
is examined. evoked response (BAER) testing is an and fluoroquinolones.
• Otic cytology: CRITICAL diagnostic test is objective test used to measure the animal’s ○ Options for yeast otitis externa include
used for identification of bacterial (rods, auditory response to sound stimulation. nystatin, thiabendazole, clotrimazole,
cocci) and yeast organisms and for leuko- • Allergy workup: elimination diet trial; miconazole, ketoconazole, posaconazole,
cytes. Any rod bacteria detected cytologically intradermal allergy testing, and serum allergy and terbinafine.
should be considered abnormal. testing (pp. 91 and 345) • Results of the otic exam are used for selection
• Ear swab: mite identification. A second • Neurologic exam (p. 1136) of the vehicle of the topical otic medication.
sample should be obtained from each ear • Mass removal/biopsy ○ Solution, lotion, emulsion, flush, or gel if
and mixed with mineral oil to assess for the ear canals range from no stenosis and
Otodectes and Demodex mites. TREATMENT hyperplasia to moderate to severe stenosis
• Otic culture: bacterial culture and sus- and/or hyperplasia
ceptibility testing is done to identify the Treatment Overview ○ Suspension or ointment if there is minimal
organism(s) in the ear and to guide the use Goals of management of otitis externa: or no stenosis or hyperplasia
of systemic (oral) antimicrobial therapy • Reduce inflammation of the ear canal with • Chronicity of the otitis is used to select the
because the results indicate the attainable glucocorticoids. specific topical otic medication.
levels in the plasma. Susceptibility testing is • Clean the ear by having the owner use ○ Acute or occasional otitis externa: first-line
generally not clinically useful for determining an otic cleaning and drying agent at topical otic medication
the appropriate topical otic antimicrobial home or by an in-hospital ear flush under ○ Chronic otitis externa: second-line topical
agent. anesthesia. otic medication

Topical Otic Treatments for Otitis Externa
PRODUCT OPTIONS FOR ORGANISMS CYTOLOGICALLY DETECTED
Rods, Cocci, and Yeast or
Otic Exam Rods and Yeast or Rods Cocci and Yeast or Cocci Only Yeast
Treatment of Acute Otitis Externa
Minimal or no stenosis or • EasOtic suspension • Claro otic solution • Claro otic solution
hyperplasia; first-line topical • Mometamax suspension • EasOtic suspension • EasOtic suspension
otic medication, active • Otomax ointment • Mometamax suspension • MalAcetic Ultra otic flush*
ingredients based on cytologic • Surolan suspension • Osurnia otic gel • Mal-A-Ket plus TrizEDTA flush*
evaluation of otic exudate • Tresaderm solution* • Otomax ointment • Miconazole 1% lotion †
containing any vehicle • Surolan suspension • Miconazole 1% lotion/dexamethasone (2 mg/mL
†
• Tresaderm solution* injectable) (1 : 1 vol. conc.), extralabel
• Mometamax suspension
• Osurnia otic gel
• Otomax ointment
• Surolan suspension
• Tresaderm solution*
• TrizUltra + Keto flush*
• T8 Keto flush*
Moderate to severe stenosis • Tresaderm solution* • Claro otic solution • Claro otic solution
or hyperplasia; first-line • Osurnia otic gel • Mal-A-Ket plus TrizEDTA flush*
topical otic medication, active • Tresaderm solution* • Miconazole 1% lotion †
ingredients based on cytologic • Miconazole 1% lotion/dexamethasone (2 mg/mL
†
evaluation of otic exudate injectable) (1 : 1 vol. conc.), extralabel
containing solution, lotion, • Osurnia otic gel
emulsion, flush, or gel vehicle • Tresaderm solution*
• TrizUltra + Keto flush*
• T8 Keto flush*
Continued

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