Your Pet's Ears

By: Lorelei Prichard DVM
About the author

The ears are more than accessories - they are the instruments of hearing. The ears detect and locate the source of sounds, while their funnel shape collects and directs the sound waves through the ear canal. Hearing is important for social interaction.

A dog’s or cat’s hearing capability is different from your own. Dogs can hear sounds at higher pitches than you do, and your cat can hear sounds at higher pitches than a dog. While the healthy young person hears sounds up to 23 kHz, dogs hear sounds to 45 kHz and cats hear sounds to 64 kHz. Like us, your pet’s hearing sensitivity often diminishes with age.

Kittens and puppies are born with closed ear canals that slowly open over a period of two weeks. Congenital deafness has been reported in over 80 breeds of dog; Dalmatians, white Bull Terriers, Australian Cattle dogs and English Setters appear to be over-represented. The deafness gene tends to be linked with white, merle or piebald coat colors. Blue-eyed, white cats also have an increased likelihood of congenital hearing loss.

The brain stem auditory response is the best means of evaluating deafness in dogs and cats, and is useful for testing litter of breeds with a high incidence of congenital deafness. With this test, small electrodes are placed under the skin of your pet’s scalp. These electrodes will detect electrical conductivity in the inner ear and the auditory pathways in the brain in much the same way that an ECG detects electrical activity of the heart. This test can confirm deafness in one or both ears and is usually offered at veterinary teaching colleges. Hearing loss should not be assessed before six weeks of age.

Some pets develop hearing loss later in life as sequelae of chronic ear infections. Although a cat’s ear canal is similar to ours, a dog’s ear canal is “L-shaped” and consists of a horizontal and vertical section. This unique shape can predispose your dog to ear infection as debris in the horizontal canal must work its way upward and outward.

Ear disease often results from a proliferation of ear wax, which occurs in response to irritation. The moist waxy build-up in the external ear then promotes bacterial and yeast colonization. Once bacteria and yeast populations set up housekeeping, your pet has an external ear infection called otitis externa. Other factors that may lead to otitis externa include excessively aggressive ear cleaning technique (e.g. using Q-tips and products not labeled for use in the ear), inappropriate treatment (e.g. treating for ear mites when none exist), and allergies. Symptoms associated with otitis externa include head shaking, rubbing and scratching the ears, odor, pain, and a change in behavior.

If an external ear infection leads to a perforated eardrum, the infection is said to have spread to the middle and inner ear. This is now called otitis media. Pets may also acquire a middle ear infection as a result of an upper respiratory infection. More common in cats than dogs, otitis media may occur as infection travels from the oral cavity to the middle ear via the Eustachian tube. A ruptured eardrum can be confirmed by your veterinarian with the use of an otoscope.

The middle ear consists of the eardrum and three small bones: the malleus, the incus, and the stapes. The inner ear is the innermost part of the ear and consists of the bony labyrinth and cochlea. These portions of the ear are dedicated to hearing and balance. If an infection reaches the middle and inner ear, your pet may have poor balance, facial paralysis, a head tilt and unusual eye movements (back and forth) called nystagmus.

Routine ear cleaning at home can augment treatment of an existing ear problem or prevent the development of a new one. In fact, some dogs are predisposed to ear issues and may need regular attention between veterinary visits. Proper cleaning at home can remove wax and dirt (as well as microbes or allergens that may contribute to inflammation or infection), flush out foreign bodies (e.g. grass awns), and clear the way for any needed medications.

If ears are waxy with no signs of infection, regular cleaning with Dr. Mike’s Melon-scented Ear Cleaner can keep ears healthy and happy. Formulated to deodorize and gently clean, dry, and acidify the ear canal, Dr. Mike’s Melon-scented Ear Cleaner provides an ideal environment for healthy ears.

Copyright © 2009 Lorelei Prichard DVM