Introduction – The Anatomy of the Canine Ear

Just as with humans, a dogs ears mainly function for hearing. The difference is the appearance. The outside part of a dogs ear is referred to as the Pinna and is sometimes floppy like a Basset Hound or straight like a Corgi. The main function of the pinna is to funnel sound into the ear canal. While human ear canals are straight, dogs are shaped like the letter “L”. The ear canal is made up of the vertical or descending canal and the horizontal canal. The latter canal ends at the eardrum or tympanic membrane. In a dogs ear the eardrum is a clear membrane and separates the external middle an inner ear.

The Common Factors that Cause Canine Ear Infections

The most common ear infection in dogs is an infection of the external part of the ear including the horizontal and vertical canals. This type of infection is called otitis externa. Otitis externa in dogs is really only caused by three things, namely ear mites, bacteria and yeast.

Otodectes cynotis or ear mites are the cause of this ear infection. It is most commonly found in puppies, but can be contracted at any age. It is highly contagious and is transferred from one infected animal to the next. These mites can also live on the head and neck.

Malassezia is the most common cause of a yeast related ear infection while Staphylococcus is the most seen factor in bacteria related ear infections. These two forms are generally more common than ear mite infections; however there are predisposing factors that can make your dog vulnerable. These factors include:

Ear canal conformation – Ear canals that are very small or longer than normal retain debris and moisture that can lead to an ear infection.

Excessive hair in the ear canal – Excess hair in the ear canal can trap water and debris leading to an ear infection.

Swimming or living in humid areas – Water retained in the horizontal canal after swimming can lead to an ear infection. In humid climates, water from the air may accumulate in the ear canal leading to an ear infection.

Folded or Floppy Pinna – If the pinnae are folded over or cover the vertical ear canal, debris and water can become trapped, thus resulting in infection.

Food Allergy – When a dog is allergic to certain foods, skin reactions can occur as well as changes in the ear canal environment. When this occurs, water is retained and the ending result is an ear infection.

Inhalant and Seasonal Allergies – These are also referred to as Atopy and include reactions to dust, mold, trees, grass and other environmental factors. Not only will your dog experience skin irritations, the environment in the ear canal will change resulting in moisture buildup which then leads to ear infections.

Systemic Disease – Hypothyroidism or other diseases that affect the endocrine system hamper the immune systems ability to fight infection. When both of these afflictions occur, an ear infection is inevitable.

A Growth or Foreign Object – If there is an abnormal mass or some kind of foreign particle in the ear, it can trap debris and moisture causing an ear infection.

Cleaning the ears too much and leaving water or cleanser in the ears may also predispose a dog to getting ear infections.

Heather Fox is an experience veterinarian who loves to write and share about her experience and knowledge about job. She started an online classroom at Clivir.com where she provide more information about Dog Flea Allergy Dermatitis Symptoms and Dog Urinary Tract Infections Symptoms.