Ear infections are one of the most common health problems that affect dogs, and these conditions can become chronic and difficult to treat. Underlying issues may be present that exacerbate the infection and prevent healing, and appropriate diagnostics are necessary to formulate an effective treatment plan. Our Town and Country Animal Hospital team wants to offer information about dog ear infections so you are prepared if your dog is affected. 

Dog ear infections—The basics

Dog ear infections typically are classified based on what part of the ear is infected. The term otitis, meaning inflammation of the ear, is used to describe each type. These include:

  • Otitis externa — The external ear canal is the passageway that leads from the outside to the eardrum. When this structure is affected, the infection is classified as otitis externa.
  • Otitis media — The middle ear is an air-filled, pressurized space between the eardrum and the Eustacian tubes. When this area is affected, the infection is classified as otitis media.
  • Otitis interna — The inner ear sits in a small cavity inside the skull and is responsible for a dog’s sense of balance and contains the hearing apparatus. When this cavity is affected, the infection is classified as otitis interna.

Dog ear infections—The causes

A dog’s ear has an L-shaped structure that makes it easier for fluid and debris to accumulate inside the ear canal, predisposing them to ear infections. Yeast and bacteria normally reside in a dog’s ear, but when these microorganisms are allowed to multiply in excess, infection can occur. Typically, dog ear infections are linked to an underlying cause that provides a suitable environment for pathogen overgrowth. These conditions include:

  • Allergies — Dogs affected by allergic dermatitis commonly have chronic or recurring ear infections. They have a weakened skin barrier and increased ear wax production, providing food for the yeast and bacteria. 
  • Hypothyroidism — Low thyroid hormone levels affect numerous body systems and can predispose dogs to skin and ear infections.
  • Cushing’s syndrome — Cushing’s syndrome causes a dog’s adrenal glands to overproduce cortisol, which reduces the dog’s ability to fight infection. 
  • Parasites — Parasites, such as ear mites, ticks, and fleas, can disrupt the ear microbiome, leading to infection.
  • Foreign bodies — Plant material, sand, and soil can be trapped in the ear canal, causing an infection. 
  • Moisture — Water accumulation in the ear canal can lead to infection.
  • Tumors or polyps — Tumors or inflammatory polyps can cause ear infections. 

Dog ear infections—The signs

Clinical signs depend on what part of the ear is infected. These include:

  • Otitis externa signs — When the external ear canal is affected, common signs include aggressive scratching at the affected ear, redness and odor around the ear, and ear discharge. The dog also may vocalize in pain when the ear is touched.
  • Otitis media signs — Nerves that innervate the face and eye run through the middle ear, and otitis media can inflame them. Potential signs include facial paralysis, pupil constriction, drooping upper eyelid, and dry eye.
  • Otitis interna signs — Otitis interna may cause hearing deficits, as well as neurological signs, including head tilt, ataxia, and nystagmus (i.e., involuntary eye movements).

Dog ear infections—Predisposed breeds

All dogs are susceptible to ear infections, but certain breeds are at higher risk. These include:

  • Floppy-eared dogs — Breeds such as cocker spaniels and springer spaniels have long, floppy ears that contain higher than normal numbers of ceruminous glands. These are sweat glands that produce earwax, and increased wax production increases the dog’s risk for ear infection.
  • Narrow-eared dogs — Breeds such as Shar-peis have narrowed ear canals that can easily trap debris.
  • Hairy-eared dogs — Breeds such as schnauzers and poodles have excess hair deep in their ear canal, which can lead to ear infections.

Dog ear infections—The diagnosis

When a dog exhibits signs of a painful ear, diagnostics include:

  • Ear examination — We use an otoscope to assess your dog’s ear canal and eardrum. Your dog may need sedation for this procedure if they are experiencing significant pain.
  • Cytology and culture — We obtain an ear swab to submit for cytology and culture to determine what pathogen is causing the infection.
  • Allergy testing — If environmental allergies are suspected, we may recommend allergy testing to determine the allergens causing the problem.
  • Food elimination trial — If a food allergy is suspected, we may place your dog on a food elimination trial to determine the problem ingredient.
  • Blood tests — If an endocrine disorder is suspected, we may perform blood tests.
  • Imaging — We may recommend X-rays or more advanced imaging techniques to determine how severely your dog’s ear is affected.

Dog ear infections—The treatment

Treatment for dog ear infections depends on the severity of the condition. Possible treatment options include:

  • Topical treatment — In uncomplicated cases, ear cleaning and topical medications can resolve the infection.
  • Systemic medications — In some cases, systemic antimicrobials are needed in addition to topical medications to address the issue.
  • Treatment for underlying conditions — If allergic dermatitis or another health condition is contributing to the problem, these issues must be treated. 
  • Surgical management — In severe cases, surgery is needed to open the ear canal and remove diseased tissue to resolve the infection and prevent recurrence.

Dog ear infections are a serious problem that require proper management to prevent recurrence. If your dog has recurring ear infections, contact our Town and Country Animal Hospital team so we can find the underlying cause and devise an appropriate treatment strategy.