Understanding Ear Infections in Dogs
A dog ear infection is an overgrowth of bacteria and/or yeast within the ear canal that often results in a build-up of waxy discharge. Dogs are more susceptible to ear infections than humans because of the ‘L' shape of their ear canal. Depending on the cause, a dog might develop an ear infection in just one ear or both ears at the same time.
There are three types of dog ear infections affecting the different parts of the ear:
– Otitis externa is the most common type and refers to an outer ear canal infection.
– Otitis interna is an infection of the inner ear.
– Otitis media is an infection of the middle ear.
Otitis media and otitis interna can be very serious and are usually the result of infection spreading from the outer ear canal. This is why it is important to learn to spot the signs of an ear infection quickly and get it treated early.
Common causes of ear infections in dogs include allergies, skin conditions, ear mites, and a build-up of wax and appear to directly cause inflammation, while others (such as certain bacteria, yeasts, or a middle ear infection) perpetuate the condition. Identifying these factors is key to successful control of inflammation. Unless all the causes are identified and treated, the condition may return.
Written by Dr. Mariella Roberts, Veterinary Surgeon, Animal Trust Vets CIC
Published February 2025
This advice is for UK pets only
Symptoms of Ear Infections in Dogs
Excessive scratching of one or both ears • Rubbing the side of their face, either along the floor or with their paw • A smelly discharge • Excessive head shaking • Redness of the inside of the ear • The ear feels hot to touch • Scabs inside the ear | Middle and inner ear infections can cause more serious symptoms such as: A one-sided head tilt • Vomiting or nausea • Loss of balance • Deafness
When to contact your vet
If you suspect your dog has an ear infection considering all symptoms above especially signs of middle ear infection which can be very serious and in need of immediate treatment.
Diagnosis of Ear Infections in Dogs
Ear exam: your vet will use an otoscope to look down each ear canal to the ear drum (tympanic membrane) to examine the ear canal, look for foreign material, and examine the ear drum. • Cytology: to look for yeast, bacteria, parasites, or other issues. This is a simple test that involves examining a sample from the ear under the microscope to identify the presence of bacteria and yeast. • Culture: although cytology can identify the presence of bacteria, a sample must be sent to the lab for culture if we want to know exactly which antibiotics will be effective and estimate severity of infection. • Imaging: occasionally, x-rays or CT scan may be advised to assess the inner ear, usually if middle ear disease is suspected. | If your pet is in too much pain or the ear canal is too swollen, a thorough evaluation may not be possible at the initial visit. Your vet may send your pet home for a few days with some medication to take down the inflammation and open the ear canal. They may also prescribe pain medications to make your pet more comfortable.
Treatment of Ear Infections in Dogs
Topical treatment: depending on the infection’s type and severity, an ear cleaner may be recommended that could be medicated or non-medicated. Typically, cleaning a dog's ears with an ear cleaner will be recommended every day or every other day while treating an ear infection. Ear cleaner should be used before applying prescribed medications. Ear medications will likely come in the form of ear drops with an applicator. Depending on the type of ear infection, ear medications may be an antibiotic, anti-fungal, or both. Some medications also include topical steroids to help with the itch. • Oral (by mouth) treatment: depending on the severity of your dog's ear infection, an oral antibiotic, antifungal, steroid, or anti-inflammatory medication may be used. • Surgical treatment: ears that have had severe chronic disease may no longer respond to medical treatments, often because the ear canal is scarred closed. The goal of surgery for these dogs is to open the ear canal or sometimes to completely remove all diseased tissue. This procedure is called a total ear canal ablation (TECA) and bulla osteotomy (BO).
Prevention of Ear Infections in Dogs
The best treatment for inflammation of the outer ear is prevention. Be sure to inspect your dog’s ears regularly. Your vet can show you how to properly clean your dog’s ears, if necessary. The frequency of cleaning usually decreases over time from daily to once or twice weekly as a preventive maintenance procedure.
The ear canals should be kept dry and well ventilated. Using drying agents in the ears of dogs that swim frequently and preventing water from entering the ear canals during bathing should minimise softening of the ear canal and decrease the frequency of bacterial or ring worm infections in moist ear canals. (Softening impairs the barrier function of the skin, which makes it easier for infection to start.) In some cases, clipping or plucking hair from the inside of the ear flap and around the ear canal improves ventilation and decreases humidity in the ears. Always ask your vet before you start this.
If your dog tends to have multiple ear infections, then talk to your vet about possible underlying causes such as dog allergies. Managing any underlying conditions can help prevent your dog from developing ear infections.
Outlook
For most dogs, the prognosis is very good; first-line treatment is effective though sometimes it can take several weeks for complete resolution of the problem. Pets who have underlying allergies are likely to need more extensive diagnostics and may need lifelong treatment for successful management.