Thorough ear canal cleaning is an integral part of management of otitis in the dog. Cleaning facilitates the removal of exudate and cerumen and allows visualization of the canal and the tympanic membrane. The extent and type of ear cleaning are determined by the severity of disease and underlying cause.
In addition, cleaning facilitates the action of medicated otic preparations. Discharge within the canal physically prevents antibiotics and glucocorticoids from reaching target areas and the presence of purulent discharge in bacterial infections inactivates many antibiotics, including polymyxin and aminoglycosides.
In mild cases of otitis externa, where the ear is not severely painful and the dog is cooperative, most owners are able to clean the ear canal prior to application of appropriate ear medications. However, if the ear is too painful to examine and/or the ear canal is occluded with debris, flushing of the external ear canal while the patient is anesthetized is often necessary.
WHAT YOU WILL NEED
Ear flushing can be performed using video otoscopy; however, it can also be safely and effectively done using a handheld otoscope (with a strong light source and operating head with magnification). In addition, you will need:
Cotton-tipped swabs for routine cytology
Ear culturettes if bacterial culture and sensitivity need to be performed
Ceruminolytic solutions (eg, dioctyl sodium sulfosuccinate [DSS], propylene glycol, squalene, urea peroxide
Aqueous flushing solutions (eg, isotonic sterile saline [0.9%])
Glass microscope slide
Range of sterile otoscope cones
Multiple 5- and 10-mL syringes
6- or 8-French polypropylene urinary catheter
The distal tip of the catheter should be cut off with sharp scissors (if the end is rough it can be smoothed with a file or by heating). This reduces the risk for damage to the tympanic membrane and also allows the flush solution to be expelled from the end rather than the side holes.
DSS = dioctyl sodium sulfosuccinate
Otoscopic Ear Canal Images
An ear canal that is hyperplastic and partially closed; glucocorticoids can be used prior to flushing to help open up the canal.
Thick tenacious cerumen within the ear canal; a potent ceruminolytic cleanser is required.
An ulcerated ear canal with mucoid discharge; a gentle water-based cleanser is preferred over a ceruminolytic cleanser.