Because pet’s ear canals have a vertical and horizontal component, debris must work its way up (instead of straight out like our ears) which predisposes them to ear infections.
Ear infections are a result of angry skin within the ear that opens the skin barrier leading to mobilization of bacteria and/or yeast. These bacteria and yeast cause discharge in the form of waxy discharge or even pus. Angry skin within the ear can be caused by allergies, ear mites, foreign objects (e.g. grass seeds), hair growth deep in the canal or ear polyps. Ears that are frequently wet are also predisposed to infections (e.g. in dog breeds that love swimming).
The infection may be in one or both ears. A pet with an ear infection will shake their head, scratch at their ears or hold the ears drooped and you may notice a bad smell coming from the ear.
Complications of Ear Infections
If the infection reaches the middle ear, affected animals may have a head tilt, a lack of balance, and unusual back-and-forth eye movements called nystagmus. These symptoms are called vestibular signs and represent a complication of middle ear infection. Middle ear infections can also cause paralysis of the facial nerve, leading to the face looking asymmetrical.
When a dog with uncomfortable ears shakes and scratches vigorously, blood vessels in the earflap may rupture. This leads to bleeding into the space between the two layers of cartilage. These haematomas require separate management whilst still treating the underlying ear infection.
Treating Ear Infections
In consultation the vet will examine the ear and likely take swabs of affected ears to examine under the microscope. This helps us determine if bacteria, yeast or both are present and what treatment is required. If the ear is not too painful it may be cleaned in consult. However sometimes the ears are so affected or painful they require an ear flush which can only be performed under general anaesthetic due to the discomfort involved. This also provides the vet with an opportunity to examine the ear canal very closely to rule out foreign objects or masses obscuring the ear canal. Occasionally the vet may recommend oral anti-inflammatories to reduce the pain and inflammation in the ear allowing better access for topical medications. Topical medications are usually the treatment of choice and most are twice daily. These will be required for a week at which point the vet will recommend a recheck to ensure treatment is working. Often another recheck a week later is also required and the vet may re-swab the ear to determine if the infection has settled.
Some dogs or cats have chronic ear problems in which the infection is not controlled by general medication or returns when general medication is discontinued. In these cases, the ear discharge should be cultured so that the precise organism can be pinpointed and treated specifically. Regular treatment at home with disinfecting ear washes should become part of the pet’s grooming routine.
Further testing may be required to determine why the infection continues to recur. Allergy is the most common reason for recurrent ear problems, but hormone imbalances can also be underlying causes.
Some ear infections simply cannot be controlled with the above steps. Any pet that is having more than 3-4 ear infections annually should be considered for surgical management. There are multiple options for surgery including opening of the vertical canal or entire ear canal removal. These are a last resort and performed by a skilled veterinary surgeon.
In most ear infections we see small round bacteria and/or yeasts which are easily managed with topical medication. However occasionally Pseudomonas bacteria are identified on microscope exam which are bacteria that are quite frequently resistant to our first line of topical treatment. If the vet identifies these rod-shaped bacteria under the microscope they may recommend culture to ensure the right medication is selected. To prevent extreme resistance it’s really important these infections are treated intensively and carefully so be sure to follow your vet’s advice and return for rechecks. Often additional medications are required.
Chronic management of ear infections
Any pet that has reoccurring ear infections should follow a careful ear maintenance regime to ensure the chance of re-infection is minimized.
- Ear-cleaning. Ears should be cleaned MAXIMUM once weekly with a liquid ear-cleaner such as Paws Ear cleaner, Epi-otic or Oto-flush. These remove bacteria and act as drying agents. Follow the instructions as per the product.
- Tissues or gauze can be used to remove obvious discharge in between ear cleaner use.
- Keep them dry. When bathing avoid wetting the ears or if they are wet dry as thoroughly as possible. For dogs that have long floppy ears, tying their ears together flapped back above their head (ear to ear) with a loose scrunchy or hair elastic after swims or baths for about an hour may help to dry the canals out (though only some dogs will tolerate this!)
- Investigate underlying allergies. As allergies quite often are involved in these cases speak to your vet about investigating the possible causes.