Canine Skin Solutions, Inc. Karen Helton Rhodes, DVM, DACVD
www.HealthySkin4Dogs.com Terri Bonenberger, DVM, DACVD
What is the best way to clean my dog’s ears?
There is a fine line between cleaning your dog’s ears too much and not enough! Not only is the frequency of cleaning important but also the actual method or process used. The technique and appropriate cleanser are often determined by the cause of the otitis. Some cases of otitis are too painful for cleaning at home during the initial phases of therapy. The choice in cleansers is typically made based on the type of secondary infection (i.e. yeast vs. bacteria). To understand how to treat your dog’s ear disease, you need to understand what might be the underlying cause (allergy, foreign body, etc.) as well as the secondary microbial invaders (yeast, bacteria, etc)
Otitis Externa (inflammation of the external ear canal) is a common clinical problem among dogs and is often a frustrating disease to cure or even control. Your veterinary dermatologist is the ear specialist for your dog. We do not have an “ear, nose & throat specialists” in the veterinary world, as are found in human medicine.
Primary and predisposing causes of Otitis Externa:
3. Contact Irritant
4. Keratinization Disorders (epidermal maturation problems)
5. Autoimmune Disorders
6. Foreign Body
7. Metabolic Diseases
8. Conformational Abnormalities (alter the microenvironment)
9. Microanatomy variability among species (ex. Cockers, Labs and Spaniels have been found to have more apocrine glands and hair follicles than mongrel dogs)
10. Excessive moisture (medications, swimming, etc. can macerate the tissue)
11.Obstructive ear disease can trap moisture and debris
12.Overzealous Cleaning ******
1. Yeast (Malassezia pachydermatis)
2. Gram positive bacteria (ex. staphylococcus)
3. Gram negative bacteria (ex. pseudomonas, proteus, etc.)
Complications which contribute to chronicity of lesions:
1. Chronic inflammation causes the epithelial lining of the ear canal to be thrown into proliferative folds, which can hinder cleansing.
2. Chronic inflammation stimulates epidermal thickening, enlarged ceruminous glands (glands that produce ear wax/cerumen), and fibrosis (scar and thickening of the tissue) which may lead to a stenotic (narrowed or closed) canal.
3. Scar tissue and calcification (mineralization) may result from chronic inflammation: may cause excessive discomfort and trap infection.
Helpful Tips when managing your dog’s ear disease:
Ear canal volume is important when determining the amount of medication to instill in the ear canal. Recent studies (2013, Flinn, et al, NAVDF) via three-dimensional computed tomography determined that the external canal in the dog has a median volume of 2.7mls (+/- 1.41ml). The old mantra of 5 drops is not sufficient. This information is vital when applying medication so as not to waste the medication as well as make sure you apply enough! On the other hand, it is NOT important when filling the canal with cleanser. It is ok to use a large amount: more is better!
Cleansers have a direct influence on otic physiology. They tend to help correct the reversal of epithelial migration seen with tissue proliferation and glandular hyperplasia. They also help remove pro-inflammatory proteolytic enzymes. The pH of the cleanser is important in that some medications are more effective in an alkaline pH. Also, some organisms tend to thrive in specific pH (some bacteria prefer an acid pH while yeast tend to prefer an alkaline pH)……..remember, we don’t want to use what they prefer but the exact opposite! As an example of typical cleansers used by the author: EpiOtic Advanced has a pH of 5.5 and TrizEDTA has a pH of 8. I tend to use EpiOtic Advanced for malassezia otitis and TrizEDTA for pseudomonas overgrowth. When using an acidic cleanser, wait before application of topical antibiotics yet ok for immediate use when administering anti-fungals. An alkaline cleanser such as TrizEDTA will enhance the antimicrobial effects of the antibiotic by changing the permeability of the bacterial cell wall, inactivate the bacteria’s efflux pump so that antibiotics cannot be extruded, and binds collagenases produced by bacteria that cause ulcers and erosions. These actions are especially helpful against pseudomonas otitis.
Let your veterinarian dictate the correct cleanser that should be used in your dog!
Techniques for home cleaning of your dog’s ear canal:
Accumulated earwax may cause several deleterious issues:
1. directly irritate the ear canal
2. produce a microenvironment conducive to infections
3. prevent medication from coming into contact with the inflamed or diseased ear tissue
4. may inactivate certain ingredients in your medications so that you are wasting your time and $
Some cleansers used by the author include:
1. EpiOtic Advanced (Virbac: salicyclic acid, docusate sodium, monosaccharides)- overall good cleanser that is non-irritating and has overall good antimicrobial qualities
2. TrizEDTA (tris EDTA): overall good cleanser and superior antimicrobial effects in that it can “punch holes” into the bacterial cell walls and make them more susceptible to medications
3. Duoxo Micellar solution (Sogeval; surfactants, phytosphingosines): best for drier wax accumulations such as cases of Sebaceous Adenitis
“At Home Ear Flushing”: frequency
1. Frequency can vary with severity of disease: daily or every other day for severe exudative cases and once or twice weekly for less severe cases of otitis externa
2. Routine cleansing to prevent infections or prevent wax buildup: tpically every other week
3. Painful ears should NOT be cleaned at home or, if absolutely necessary, then very gently!!! There is a phrase that is often used that states “No Rush To Flush!” Painful ears are often treated with a steroid containing product for 2-4 days before flushing is started. This allows inflammation to subside and will actually make the flushing better accepted by the pet.
“At Home Ear Flushing”: simple technique
1. The ear is filled with the cleanser and massaged to loosen any debris in the canal. The debris form the canal is then wiped with cotton form the surface.
2. The process is repeated until no debris is noted to surface.
3. Q-tips are to be avoided as they tend to push debris deeper into the canal
4. Loose cotton or cotton balls can be used to remove debris from visible crevices.
5. Some medications (such as Zymox) are enzymatic treatment that can dissolve wax and help owners avoid the need to “home flush”
Deep Cleaning: Anesthetic Video-Otoscopy Cleaning by your veterinarian
1. Necessary in severe cases or chronic cases in order to “create a clean slate” that allows medications to be effective!
Also, remember that over-cleaning can actually macerate sensitive tissue. Cleansers are best administered warm (especially in the cat). At my office, we keep our cleansers in the incubator for comfort and ask owner to keep cleanser at room temperature at home. Some ingredients in cleansers have been associated with potential toxicity: propylene glycol, chlorhexidine @ >0.2%, DSS, carbamide peroxide, and triethanolamine.