Common Ear Infections (and Causes) in Dogs
Drs. Foster & Smith Educational Staff

Have you noticed an unpleasant odor coming from your dog’s ears, repeated pawing at his head, a discharge, or visible redness and swelling in an ear? Does your pet’s ear appear to be painful? If so, there is likely an ear infection underway, and any inflammation/infection in the ear is cause for immediate concern and action.

Two major types of infections occur in the dog’s ear; most common is otitis externa, an infection of the outer ear, including the ear canal up to the ear drum. More rare is otitis media, an infection of the canal behind the eardrum. All ear infections, if untreated, can lead to consequences that range from mild to severe. Especially in the case of infections behind the eardrum, the condition can lead to deafness, facial paralysis, loss of balance, and other neurological problems, which may be irreversible.


  • Odor
  • Scratching or rubbing of the ears and head
  • Discharge in the ears
  • Redness or swelling of the ear flap or canal
  • Shaking the head or tilting it to one side
  • Pain around the ears
  • Changes in behavior such as depression or irritability

Ear infections are caused by a variety of factors. It is important to note that the more serious condition of otitis media is often the direct result of an untreated case of outer ear infection.

Causes of serious ear infections include:

  • Bacteria and yeast
  • Moisture in ear canal following bathing or swimming
  • Ear mites
  • Allergies
  • Foreign bodies (such as plant awns)
  • Injury
  • Hormonal abnormalities, or any kind of compromised immunity

In short, anything that can cause itching may lead to intense scratching and trauma, which can open the door to a serious infection.

Prevention begins with a regimen of care to keep the outer ears clean and free of debris. Dry ears after bathing/swimming. Allergies must be controlled, and any ear mite infections treated. All possible conditions that could lead to ear infections must be assessed and treated by your veterinarian to prevent bacteria and yeast from gaining a foothold.

Your veterinarian can teach you how to provide ongoing care and suggest products to use to keep your dog’s outer ears clean. Along with controlling mites and allergies, this is an effective strategy for keeping ear infections at bay. Not all ear problems can be prevented. If caught early, however, treatment is generally successful.