Ear infections are a common problem in dogs, and a leading cause of veterinary visits. This condition is painful and, left untreated, can result in permanent hearing loss. Our Columbia Pike Animal Hospital team does not want your dog to suffer long-term consequences from this seemingly minor problem. 

Primary causes of dog ear infections

Bacteria, such as Staphylococcus and Pseudomonas species, and yeast, such as Malassezia pachydermatitis, normally inhabit the dog’s ear, but when certain conditions allow these pathogens to multiply, infection can occur. Primary causes that lead to infection in a normal ear include:

  • Parasites — Parasites, such as ear mites and mange mites can lead to infection.
  • Allergies — Allergic dermatitis weakens the skin barrier and increased wax is produced, allowing infection to occur. Environmental, flea-bite, and food allergies are the most common hypersensitivity disorders seen in dogs, and dogs who suffer from recurrent ear infections are commonly affected by allergic dermatitis. 
  • Endocrine disorders — Endocrine diseases, such as hypothyroidism and hypercortisolism, cause changes in the dog’s hormone levels, which can lead to infection.
  • Foreign bodies — Foreign bodies, such as hair, plant material, soil, and sand, that become trapped in the ear canal can cause infection.
  • Growths — Tumors and benign inflammatory polyps growing inside the ear can lead to infection.

Predisposing factors of dog ear infections

Some dogs have predisposing factors that exacerbate inflammation and alter the ear canal microbiome, allowing pathogens to invade. These factors include:

  • Conformation — Dogs have an “L” shaped ear canal that traps debris, which provides food for bacteria and yeast. In addition, dogs who have pendulous ears are at higher risk for ear infections, because this conformation creates an ideal, moist environment for pathogens. 
  • Breed — Certain breeds, such as cocker spaniels, Shar-peis, German shepherds, and poodles, are at increased risk.
  • Excessive moisture — Dogs who swim frequently are at higher risk, because moisture becomes trapped inside their ear.
  • Immunosuppression — Dogs who take immunosuppressive medications or are affected by an immunosuppressive disease are at increased risk.
  • Over treatment — Excessive cleaning or improper cleaning methods (e.g., using cotton swabs) can lead to infection.

Perpetuating factors of dog ear infections

Perpetuating factors prevent infection resolution by aggravating the inflammatory process. Factors include:

  • Progressive changes — Chronic infection results in tissue thickening inside the ear, leading to ear canal stenosis and calcification. 
  • Infection progression — When the infection affects the middle and inner ear, treatment is more difficult.
  • Tympanic membrane abnormalities — Scarring or rupture of the tympanic membrane (i.e., eardrum) can exacerbate an ear infection. 

Dog ear infection diagnosis

Dogs affected by an ear infection typically show signs that include shaking their head, scratching at the infected ear, odor from the ear, and ear discharge. When the infection progresses to the middle and inner ear, neurological signs may also be present. Steps to diagnose your dog’s condition typically include:

  • History — We obtain a thorough history about your dog’s previous ear infections and skin disorders, as well as how they were treated.
  • Ear examination — We flush out your dog’s ear, and use an otoscope to carefully evaluate the ear canal and tympanic membrane. Sedation or anesthesia may be required, because this procedure can be extremely painful for your dog.
  • Culture — We take a sample swab to submit for culture and sensitivity, to learn what pathogen is causing the infection and what antimicrobial will be effective.
  • X-ray — X-rays can detect mineralization in the ear canal and bony changes in the deeper ear structures.
  • Ultrasound — This imaging technique can detect thickening and fluid accumulation inside the ear canal.
  • Advanced imaging — Advanced imaging techniques, such as magnetic resonance imaging or computed tomography, are sometimes needed to fully assess ear infection damage.

Dog ear infection treatment

In simple cases, treatment involves cleaning your dog’s ear and administering an appropriate topical antimicrobial. In more complicated cases, we may recommend additional treatments, including:

  • Systemic medications — We may prescribe systemic antimicrobials or pain medications.
  • Managing primary causes — If we diagnose a primary cause, such as allergic dermatitis or an endocrine disorder, we will recommend a treatment plan to address these issues.
  • Surgery — In severe cases, surgery is needed to remove the affected tissue to resolve the infection and prevent recurrence. 

Dog ear infection prevention

Your dog’s ear conformation makes them prone to ear infections, but you can take steps to decrease their risk. These include:

  • Drying your dog’s ears — Dry your dog’s ears after swimming or bathing to prevent moisture accumulation in the ear canal.
  • Cleaning your dog’s ears — Regularly clean your dog’s ears using a veterinary approved ear cleaning solution.
  • Providing parasite prevention — Year-round parasite prevention will protect your pet from parasites that can cause infection.
  • Monitoring your dog’s ears — Evaluate your dog’s ears daily to monitor for infection signs, so you can seek veterinary care as soon as possible.

Ear infections are painful conditions that can lead to hearing loss, and should not be ignored. If your dog’s ear is causing problems, contact our Columbia Pike Animal Hospital team, so we can determine the primary cause and alleviate their pain.