Many factors contribute to chronic ear infections, which are common in dogs and can be difficult to manage. Our team at Belmont Animal Hospital wants to offer information about chronic ear infections and explain ways you can decrease your dog’s risk.

Dog ear infections

Ear infections in dogs are typically classified depending on the ear region affected. Classifications include:

  • Otitis externa — Otitis externa causes inflammation in the external ear canal, which is the tube between the outer ear and eardrum. Signs in dogs include head shaking, redness, swelling, malodorous discharge, and pain.
  • Otitis media — Otitis media causes inflammation in the middle ear, the air-filled space behind the eardrum. These infections most commonly develop after an existing otitis externa infection damages the tympanic membrane, and the infection extends into the middle ear. Certain nerves course through the middle ear, and an infection in this area can result in signs that include facial nerve paralysis, dry eye, and abnormal eye movements.
  • Otitis interna — Otitis interna causes inflammation in the inner ear, including the cochlea, vestibule, and semicircular canals. Signs include hearing loss, head tilt, circling, and incoordination.

Primary causes of dog ear infections

Dog ear infections are a multifactorial issue, with the infection usually only part of the problem. Primary causes initiate inflammation inside the ear canal, change the ear environment, and cause otitis externa in a normal ear. These include:

  • Parasites — Parasites, such as ear mites, mange mites, and ticks, can cause a primary ear infection.
  • Hypersensitivity disorders — Allergies, including reactions to fleas, food, and environmental allergens are common in dogs and can result in a primary ear infection.  Allergies are the primary underlying cause for most ear infections.
  • Endocrine disorders — Endocrine disorders, such as hypothyroidism and hypercortisolism, can cause otitis externa.
  • Foreign bodies — Foreign bodies, such as plant material, hair, sand, and hardened medications, inside the ear canal can cause a primary ear infection.
  • Tumors — Benign growths, malignant tumors, and inflammatory polyps can cause otitis externa.

Secondary causes of dog ear infections

Secondary causes are those that cause disease only in an abnormal ear. These include:

  • Bacteria — Various bacteria can cause secondary bacterial infections, with Staphylococcus and Pseudomonas species the most common culprits.
  • Yeast Malassezia pachydermatis is another common pathogen that causes secondary ear infections. 

Once identified, secondary causes are typically easy to treat, and should they become chronic, primary causes and perpetuating factors are usually complicating the condition.

Predisposing factors for dog ear infections

Predisposing factors increase a dog’s risk for otitis externa development and persistence. These include:

  • Conformation — A dog’s ear canal is L-shaped and tends to hold fluid, predisposing them to ear infections. Other conformational factors that increase a dog’s risk include narrowed ear canals, long, droopy ears, and excessive hair growth inside the ear canal.
  • Breed — Certain breeds, including cocker spaniels, German shepherds, poodles, and basset hounds are at increased risk.
  • Excessive moisture — Dogs who swim frequently are at increased risk.

Perpetuating factors for dog ear infections

Perpetuating factors, which prevent otitis externa resolution, include:

  • Ear canal scarring — Chronic infection can cause ear canal scarring, which makes the condition difficult to clear.
  • Abnormal tympanic membrane — Scarring and tympanic membrane rupture can complicate otitis externa.
  • Otitis media and interna — Progressive infection inside the ear can make resolution difficult.

Treating dog ear infections

Treating dog ear infections is straightforward in uncomplicated cases, but certain issues can make management challenging. Treatment involves:

  • Ear cleaning — Cleaning agents are used to soften and remove inflammatory debris inside the ear as well as to decrease moisture and balance the pH. This procedure may require sedation or anesthesia if the dog is too painful to cooperate.
  • Topical treatment — Topical treatments are important in treating dog ear infections because most contain steroids and antibacterial or antifungal agents.
  • Systemic medications — In some cases, systemic antibiotics or antifungals may be necessary to control the infection.
  • Addressing primary causes — If your dog has an allergy or endocrine disorder, these conditions must be addressed to help prevent recurrence.

Surgically managing dog ear infections

In severe cases involving tumors or excessive scar tissue, surgery may be necessary to address the ear infection. Surgical procedures include:

  • Lateral ear canal resection — This technique is helpful for dogs who have narrowed ear canals or masses in the vertical ear canal, because the procedure may improve ear environmental factors and facilitate medical management.
  • Vertical ear canal resection — This procedure is used for vertical canal masses.
  • Ventral bulla osteotomy — This technique is used to remove middle and inner ear tumors or polyps.
  • TECA-BO — This procedure, which involves a total ear canal ablation and a lateral bulla osteotomy, is used to address chronic, end-stage ear infections and tumors that can’t be removed by other methods.

Preventing dog ear infections

Not all dog ear infections can be prevented, but you can take steps to decrease your dog’s risk. These include:

  • Cleaning your dog’s ears — Regularly clean your dog’s ears to help prevent debris and fluid accumulation. Belmont Animal Hospital can recommend ear flushes to help with cleaning
  • Drying your dog’s ears — Dry your dog’s ears thoroughly after cleaning and after they go swimming.
  • Controlling primary causes — If your dog is diagnosed with an allergy or endocrine disease, ensure you follow all recommendations to help control the condition.

Chronic ear infections can be challenging, but keeping your dog’s ears clean and dry will help decrease their risk. If your dog has a painful ear, contact our Belmont Animal Hospital team, so we can determine the best way to alleviate their distress.