Ear infections are a common malady in dogs, causing them extreme pain and significant health complications. Our American Animal Hospital Association (AAHA)-accredited team at Cherry Knolls Veterinary Clinic wants to help by providing information about canine ear infections and describing the steps you can take to prevent the condition.

Canine ear infection causes

Canine ear infections can affect the ear canal (i.e., otitis externa), the middle ear (i.e., otitis media), and the inner ear (i.e., otitis interna). These multifactorial conditions typically appear secondary to a primary cause. In addition, some dogs are simply predisposed to ear infections, putting them at a higher infection risk:  

• Predisposing factors — The canine ear canal is more vertical than a human’s, making fluid accumulation more likely, and putting dogs at a higher ear infection risk. Long ears, a narrowed ear canal, and excessive ear canal hair are also factors that predispose dogs to ear infections. Certain breeds, including cocker spaniels, German shepherd dogs, poodles, basset hounds, are genetically predisposed to ear infections, and water-loving dogs are at a higher risk.
• Primary causes — The most common primary canine otitis externa cause is hypersensitivity disorder. Allergies, including flea bite hypersensitivity, food allergies, and environmental allergies, cause excessive itchiness, and when your dog’s scratching disrupts their ear’s normal defenses, enable secondary infection. In addition, inside an allergic dogs’ ears, normal yeast and bacteria tend to overgrow, causing infection. Other primary ear infection causes include parasites, endocrine disorders, autoimmune disorders, foreign bodies, and tumors.
• Secondary causes — The most common secondary ear infection causes are bacteria (e.g., staphylococcus and pseudomonas species) and yeast (e.g., Malassezia pachydermatis, Candida albicans).

Dogs affected by chronic ear infections typically develop changes, such as scarring and narrowing inside the ear canal, that can perpetuate the ear infection, making resolution difficult. 

Canine ear infection signs

If your dog has an ear infection, initial signs can include excessive ear canal wax accumulation, but as the condition progresses, your pet can experience significant discomfort. Signs for the different infections include:

• Otitis externa — Signs include head shaking, scratching the affected ear, ear discharge and odor, ear canal redness and swelling, and vocalization when the ear is touched. 
• Otitis media — Signs can include deafness, keratoconjunctivitis sicca (i.e., dry eye), and Horner syndrome (i.e., a disruption in the nerve pathways from the brain to the face and eye, resulting in a drooping upper eyelid, prolapsed third eyelid, and a constricted pupil). 
• Otitis interna — Signs include head tilt, incoordination, and nystagmus (i.e., uncontrollable eye movements).

Canine ear infection treatments

Since most ear infections stem from a primary cause, simply treating the infection is not enough to resolve the issue and prevent recurrence. A diagnostic investigation is necessary to determine the primary cause behind your dog’s ear infection:

• History — Provide your veterinary professional with your dog’s complete health history, including  known allergies, underlying medical conditions, diet, swimming frequency, regularly scheduled ear cleanings, and ear infection history. 
• Physical examination — Your veterinarian will give your dog a comprehensive physical examination including ear canal and ear drum evaluations, using an otoscope. 
• Cytology — Your veterinary professional will inspect a sample from your dog’s ear, using a microscope to identify pathogens.
• Culture — Your veterinarian may culture the discharge from your pet’s ear canal to determine the most appropriate antibiotics or antifungals to treat the infection.
• Blood tests — Blood tests may be necessary to rule out an endocrine disease or other underlying condition.
• Dietary elimination trial — Your veterinarian may recommend that your pet undergo a dietary elimination trial to rule out a food allergy.
• Imaging — Your veterinarian may recommend skull X-rays to further assess the extent of middle ear and inner ear disease. 

If your veterinarian diagnoses your dog with an allergy or another underlying health issue, they will address this condition to help manage your dog’s ear infection. They may also recommend regular ear cleaning, topical medications, oral antibiotics, and anti-inflammatory medications. If your dog has a severe ear infection, your veterinarian may recommend a total ear canal ablation (TECA) surgery to remove the diseased tissue, helping prevent ear infection recurrence.

Canine ear infection prevention

Excess moisture commonly leads to ear infections, so ensure you dry your dog’s ears thoroughly after a swim or bath. In addition, cleaning your dog’s ears weekly can help prevent infections. To clean your dog’s ears correctly, follow these steps:

• Use the correct product — Use a product recommended by our veterinary professionals.  Human ear cleaning agents, such as hydrogen peroxide, rubbing alcohol, and witch hazel, can irritate your dog’s ear canal.
• Use enough product — Completely fill your dog’s ear canal with the ear cleaner, provided their eardrum is intact.  
• Massage your dog’s ear — Gently massage your dog’s ear base until the cleaning solution makes a squishing sound.
• Clean out debris — Use a cotton ball to absorb the cleaning solution and ear debris. Repeat this step using fresh cotton balls until the ball comes out clean.

Ear infections can cause your dog significant pain and may lead to serious complications, if not addressed appropriately. If your dog is exhibiting ear pain signs, contact our Fear Free team at Cherry Knolls Veterinary Clinic, so we can treat the ear infection’s primary cause and ease your dog’s distress.