Ear Infections (Otitis Externa) in Dogs

Ear disease is one of the most common conditions treated by veterinarians. Otitis externa is the term used to describe inflammation of the outer ear canal. Unlike the horizontal shape of the human ear canal, a dog’s ear canal has a more vertical shape, making it an ideal place for debris and moisture to build up.

The ear canal is a sensitive structure and prone to infection, although this is more true in some dogs than in others. Dogs that have heavy, pendulous ears tend to be more predisposed to developing ear infections because of the lack of air circulation, while other breeds of dogs, such as Shar-Peis, naturally have a narrower (stenotic) ear canal. There are some breeds that naturally have an abundance of hair surrounding the ear canal, which blocks air circulation and may cause blockages of loose hair. Dogs with allergic skin disorders such as canine atopy and food sensitivity dermatitis tend to have more frequent ear infections as part of the overall allergic response. Other causes of ear infections include bacteria, yeast, and parasites such as ear mites. Foreign objects may enter the ear canal, causing irritation. As a dog scratches, they cause self-inflicted trauma, which makes ear problems worse. Hormonal deficiencies or excesses can affect the ears, such as in dogs with hypothyroidism, and may require treatment to prevent ear problems in the future. Occasionally, hereditary diseases such as dermatomyositis and primary seborrhea affect the ears, as well as squamous cell carcinoma, melanoma, and other tumors in the ear.

The normal appearance of a dog’s outer ears on the inside of the ear flap should be pale pink, smooth, with no foul odor or discharge. The following symptoms may indicate the need for veterinary examination of the ears:

Scratching of the ear area, head shaking, or tilting

Rubbing of the ear on the floor or furniture

Foul odor in the ear

Redness, swelling, crusting, discharge, or buildup of the outer ear or canal, hair loss around the ear

Pain around the ear area

Hearing loss, loss of balance, or walking in circles

If you notice any of these symptoms in your dog, they should be brought to a veterinarian for treatment right away, because external ear infections may spread to the middle ear and cause complications or permanent deafness. The veterinarian may use an otoscope, a tool used to examine the inside of the ear canal and eardrum, as a first step toward diagnosing the specific cause of your dog’s otitis externa. A sample of discharge from the ear canal may be taken and examined under the microscope or sent off to a laboratory to find out if any specific species of bacteria, yeast, or ear mites are involved. This will help determine what the best treatment plan is for the dog. In dogs whose ear canals are filled with too much debris for the veterinarian to see inside, or for those who are in too much pain for examination, sedation may be required so that the ears can be cleaned enough to examine.

Depending upon the cause of the ear problem, treatments could include antibiotics, antifungals, or ear mite medications. Treatment of the underlying cause of the infection may include allergy treatment, thyroid treatment, or removal of tumors or hair that may be blocking the ear canal.

Regardless of the cause of your dog’s ear problems, keeping the ear canal clean and dry is the first priority, and the best way to prevent further ear infections. Always follow your veterinarian’s recommendations to help keep your dog’s ears clean and healthy.