One of the reasons dogs are such great companions to humans is because they alert us to so many things that we would otherwise overlook. This includes sounds that our own hearing isn't sensitive enough to catch. A dog, on the other hand, has an acute sense of hearing, thanks to the structure of his ears. Simply looking at the variety of dog ears is a reminder of the range of canine anatomy. A dog's ears can be pricked in the air or folded over like the dog-eared page of a book. They might be large or small, long or short. But on the inside, every dog's ear is a masterpiece of acoustics.

Ear Anatomy

Sound is energy, or vibrations, that is transmitted by waves through the air. You may have noticed that your dog can wiggle his ears much more than you can yours. He can rotate his ear flap (known as the pinna) to capture sounds, which then travel into the ear canal. From there the sound flows through the ear canal downward and inward until it arrives at the eardrum, or tympanic membrane. A chain of small bones called the auditory ossicles then transmits the sound to the inner ear, which has been described as resembling a series of bony canals. The inner ear is the essential organ of hearing and contains the cochlea. Coiled like a snail shell, the cochlea is filled with fluid that converts the vibrations making up sound into waves that in turn become nerve impulses transported to the auditory nerve where they are interpreted by the brain. As with the process of sight, all of this occurs instantaneously.

Ear Problems

As much as 20 percent of a veterinarian's practice consists of treating ear infections and other ear problems. Ears can become infected with bacteria, fungi, or yeast. They can sustain injuries in fights or play, and they can become infested with mites. Allergies can cause ear problems, and dogs can suffer congenital or acquired deafness.

Except for the external ear, dogs and humans have similar ear anatomy, but dogs can hear high-pitched sounds that are inaudible to humans and can hear sounds from a much greater distance than people.

If your dog frequently shakes his head and paws at his ears, he may have an infection. Ear infections are treated with antibiotics. Your veterinarian will need to culture the buildup in the ear to determine what's causing the infection. This allows her to prescribe the best antibiotic for the job. Itching and inflammation caused by allergies calls for use of the big guns: antihistamines and corticosteroids.

If your dog's ear flap is wounded, you'll need to stop the bleeding and apply antibiotic ointment to the injured area. A serious laceration may need stitches. Bite wounds often become abscessed, so keep an eye on the area to make sure it doesn't become swollen and tender.

With good care, however, many ear problems can be avoided. Keep your dog's ears clean and dry. Wipe them out with a cotton ball after your dog has a bath or goes swimming. Clean the ears whenever you see a buildup of wax or dirt in the ears. Use an ear cleaner recommended by your veterinarian and avoid products that contain alcohol, which stings.

Check the ears frequently to make sure nothing is stuck inside them. Dogs can get grass seeds or other objects caught inside their ears. If they're not removed, an infection can begin. Be careful not to push the object further into the ear. If necessary, take the dog to your veterinarian to have the object removed.