A dog’s external ear consists of a vertical and horizontal canal that is separated from the middle ear by the tympanic membrane (ear drum). When a dog develops an external ear infection, known as otitis externa, they usually shake their head and scratch their ears. A person might notice discharge in and around the dog’s ear, an odor to the ear, and redness and swelling of the ear canal and pinna (ear flap).
Some dogs with ear infections will develop an aural (ear flap) hematoma from scratching their ear or aggressively shaking their heads, and rupturing a blood vessel inside the pinna. The blood accumulates between the two surfaces of the ear creating a balloon-like fluid-filled area. There are several types of treatment for an aural hematoma that range from draining the hematoma with a needle to performing a surgical procedure under general anesthesia. Even with proper treatment the hematoma can recur and possibly cause scarring which deforms the shape of the pinna.
If a dog is suspected of having an ear infection it is recommended that a veterinarian examine the dog. A veterinarian will need to evaluate the dog’s ear with an otoscope to visualize the ear drum to see if it has been ruptured, and the ear canal for signs of infection and possible foreign object such as a grass awn. If a veterinarian suspects the dog has an ear infection they will need to take a sample of the ear discharge to examine it under the microscope for bacteria and yeast.
After a veterinarian determines the dog has an ear infection they will need to clean the debris from the dog’s ear canal. Typically this procedure is done with the dog awake, unless the ear is so painful that sedation is required. The cleaning solution is instilled into the dog’s ear canal to break up the debris and allow for easier removal of the debris with tissue or cotton balls. It is not recommended to clean the ears with a cotton swab because this can damage the ear drum. Some dogs will benefit from having their ears flushed under general anesthesia if they have a severe infection. After the dog’s ears have been properly cleaned a medication can be applied to reduce the inflammation and treat the infection. This will typically need to be done on a specific regimen for at least 2 weeks. Following the treatment a veterinarian will need to re-examine the ear to determine if the infection has resolved.