Otitis externa is a common complaint in dogs. The percentage of canine cases presenting for otitis externa ranges from 7.5% to 16.5% This condition is an inflammation of the external ear canal consisting of the pinna ( the ear-flap), and the vertical and horizontal ear canals up to the level of the ear drum or tympanum.
In many instances of otitis externa there is secondary infection with a fungus such as Malassezia pachydermatis, or a bacterial infection such as Pseudomonas aeruginosa, Staphylococcus pseudintermedius, Escherichia coli, and Klebsiella spp. Pseudomonas aeruginosa is the most common Gram-negative bacillus and is found in soil, water, and decaying organic matter. It is not a normal inhabitant of the canine ear and when it leads to infection, it can be challenging to manage and treatment is further complicated by the growing number of multidrug resistant strains.
Dogs with heavy, pendulous ears and with fur growing in the external ear canal ( which should be routinely removed) are prone to develop the kind of moist conditions that are ideal for the proliferation of these microorganisms. So genetics in terms of ear conformation and fur around the pinna play a significant role in dogs developing Otitis externa. Also, food allergies and autoimmune disease may play a role along with nutrient deficiency, especially in omega 3 fatty acids.
For dogs with ears like the Cocker spaniel it often helps to tie a ribbon to the fur on the end of each ear and then lift the ears up and tie the ribbons on the top of the dog’s head for a few hours. This is best done in the evening when the dog is quiet and especially after routine era cleaning.
Veterinarians can supply appropriate cleaning products to help with “moist” and “dry” external ear canals. High humidity in summer and warmer Sates and low indoor humidity in winter can both take their toll on dogs’ external ear canals. As a general health-maintenance practice I advise a few drops of organic, cold-pressed olive oil on a cotton ball be worked in to each ear canal. Help may be needed to keep the dog’s head still.
When there is evident inflammation and the dog is scratching and rubbing one or both ears and head-shaking, an immediate veterinary appointment is called for. Otherwise, infection could spread to penetrate the ear drum and cause middle-ear disease, disrupting balance, and even causing loss of hearing. Violent head-shaking can break blood vessels in the pinna which turns into a blood-blister/hematoma. This will need surgical correction to prevent a crumpled-ear developing as the blood clot shrinks.
When treatment for fungal or bacterial infection is delayed or is ineffectual, the inflamed external ear canals become thickened and corrugated with pockets that are impossible to properly clean. So surgical opening of part of the ear canal is called for.
In many instances where conventional anti-fungal and antibiotic treatments fail, dogs can be helped by the OTC product called Zymox Plus. Alternatively, rinsing each external ear canal with warm aloe vera liquid every week may help. When the ear canals are dry, then use a cotton ball to deliver a good smearing of a mixture of 100 drops of olive oil and 10 drops of by weekly treatment with 100 drops of olive oil and 5 drops each of essential oils of Thyme and Lavender, known for their antiseptic and anti-inflammatory properties.
Dogs having acute and painful external ear issues may need sedation and analgesia—in some instances an invading grass seed awn may be the culprit or ear mites from an infested cat in the home or neighborhood. Fur loss and redness behind one or both ears should not be mistaken for a local skin infection but a result of the dog scratching because of the discomfort in the external ear canal. Also, cancerous growths can develop in the external ear canal and require biopsy testing and surgical removal.