Ear Infections in Cats and Dogs

Ear Infections in Cats and Dogs

Animals affected

Cats and dogs of any age.


Ear infections are common and painful problems for pets. In cats and dogs, ear infections typically are opportunistic and not contagious. They often occur when the ear’s immune system is disrupted by allergies, moisture, poor air circulation, or diseases such as feline AIDS. Under these conditions, bacteria and yeast that normally live harmlessly in the ear are able to proliferate to the point of infection.


Ear infections may cause one or more of the following symptoms.

  • Head shaking
  • Holding the ear back or down
  • Redness in the ear
  • Production of wax, pus, or blood in the ear
  • Foul odor from the ear
  • Scratching or rubbing the ear on the ground
  • Ear pain
  • Tilting the head to one side

Risk Factors

  • Breed and ear shape: Animals with long, limp ears suffer from poor air circulation and have high rates of ear infections. Breeds with this type of ear include Labrador and Golden Retrievers, Basset Hounds, and Spaniels. Breeds with exceptionally small outer ears, such as Shar Peis, Scottish Folds, and Persian cats experience high rates of ear infections as well.
  • Pets that swim may suffer excess moisture in their ears, leading to infections.
  • Flea allergies and infestations are leading causes of ear infections.
  • Allergic reactions to pollen, environmental allergens, and food contribute to ear infections.
  • Diseases or conditions that weaken the immune system, such as feline AIDS, lead to higher rates of ear infections.
  • Hair in the ear canals can trap moisture and trigger infections.


Ear infections are painful and always should be treated. Chronic, untreated ear infections can lead to the following problems.

  • Severe chronic pain that may require surgery to correct
  • Hearing loss
  • Neurological symptoms including loss of balance
  • Hematomas, manifested by profound swelling when blood accumulates in the tissues of the outer ear, can result from excessive head shaking. Hematomas are painful and difficult to treat.


Ear infections are diagnosed by visual inspection of the ear. Microscopic evaluation or bacterial culture of ear discharge may aid in the diagnosis.

Treatment and Prevention

Mild infections usually are treated topically.

  • Ear cleansing with specially designed veterinary otic ear washes removes wax, debris, and infectious agents. Ear cleansing must be performed daily in most cases because infections cause continuous excessive ear wax production.
  • Treatment with an otic ointment, typically containing an antibiotic, an anti-fungal agent (for yeast) and cortisone (to relieve pain and inflammation) is implemented once or twice daily in most cases.

Severe cases may require oral medication.

  • Antibiotics help to fight severe or deep bacterial infections.
  • Oral anti-fungal agents help to remove yeast.
  • Oral corticosteroids, such as prednisone, reduce swelling, inflammation, and pain.

Prevention of ear infections involves reducing the effects of risk factors that contribute to ear infections.

  • Periodic cleaning removes moisture and debris.
  • Ear plucking eliminates hair from the ear canal.
  • Use of flea preventatives reduces allergic reactions to fleas.
  • Rarely, antihistamines or even corticosteroids may be prescribed by veterinarians to prevent recurrent or chronic ear infections.


Mild ear infections typically resolve completely with one week of topical therapy. Severe or recurrent infections may require much longer and more aggressive courses of treatment. Depending on the nature of the infection, a follow-up examination with a veterinarian may be necessary to ensure that no residual infection persists.



Animals that are predisposed to ear infections typically suffer from multiple infections over their lifetimes. These animals benefit from the preventive home care techniques discussed above.

Human ear infections typically involve the middle ear. Common animal ear infections are different, affecting primarily the ear canal and outer ear.

Copyright © Eric Barchas, DVM All rights reserved.
The contents of this page are provided for general informational purposes only. Under no circumstances should this page be substituted for professional consultation with a veterinarian.