Otitis Media and Interna in Cats
Inflammation of the middle ear structures (otitis media) is usually caused by an extension of infection from the external ear canal or by penetration of the eardrum by a foreign object. Inflammatory polyps are also a common cause of otitis media in cats. The spread of infection through the bloodstream to the middle ear is also possible, but it is rare. Inflammation of the middle ear may lead to inflammation of the inner ear structures (otitis interna). This can in turn lead to loss of balance and deafness. In general, otitis media and interna are more serious than otitis externa, and their effects on the ear may not be reversible.
Signs of otitis media include head shaking, rubbing or scratching the affected ear, and tilting or rotating the head toward the affected side. Signs of an external ear infection (otitis externa) may also be present.
Because some of the nerves of the face travel through the middle ear, a cat's face may show signs. Otitis media can cause facial nerve paralysis, constriction of the pupil of the eye, drooping of the eyelid, sinking of the eyeball into the eye socket, and protrusion of the third eyelid on the same side as the affected ear. If otitis interna occurs at the same time, the cat may tilt its head toward the affected side. Additionally, a cat with inflammation of the inner ear may have an overall lack of coordination severe enough to cause difficulty in rising and walking. An involuntary rhythmic movement of the eyes from side to side (called nystagmus) may also be seen with inflammation of the inner ear. If the inflammation spreads to the brain, neurologic signs can be seen. If your cat is having problems with balance, walking, or jumping, you should suspect a middle ear problem and take your pet in to the veterinarian promptly.
Your veterinarian may diagnose otitis media when the eardrum is ruptured, either by a foreign object or longterm inflammation. It is difficult to diagnose if the ear drum is not ruptured. Otitis interna may be diagnosed when signs of otitis media are seen in addition to a loss of balance. When external ear inflammation is also present, your veterinarian will do tests to identify the cause (such as mites, a foreign object, or a bacterial infection). Your veterinarian may also take a sample from the middle ear to perform a culture that can identify any bacterial infection. X-rays, computed tomography (CT scan), or magnetic resonance imaging (MRI) may be used to detect inflammation of the middle or inner ear or hardening and fibrous overgrowth of the round bone behind the ear.
Because of the possibility of hearing loss and damage to the organ of balance (vestibular apparatus), longterm antibiotics given by mouth or injection may be prescribed by your veterinarian to treat otitis media or interna. Treatment may last 3 to 6 weeks. If the eardrum is ruptured, your veterinarian will carefully clean the middle ear. Small perforations of the eardrum usually heal in 2 to 3 weeks. Any inflammation of the external ear canal will be treated at the same time. Additionally, anti-inflammatory medications may be prescribed during the first week of treatment to decrease pain and inflammatory changes in nearby nerves. Ear mites, if present, are treated with antiparasitic drugs. If you cat does not respond to medications, surgery may be necessary to resolve the issue.
Otitis media with an intact eardrum usually responds well to antibiotic therapy. However, if longterm inflammation of the inner ear exists and the eardrum is ruptured, the chances of successful treatment are reduced. If local nerve problems develop, they may continue even after the infection has been cleared. Inflammation of the inner ear usually responds well to longterm antibiotic therapy, but some neurologic problems (for example, lack of coordination, head tilt, deafness, drooping lips, or inability to blink) may persist for life. Animals recovering from inflammation of the inner ear should be given adequate time to adapt to any persistent nerve-related signs.
The sooner cats with middle or inner ear inflammation can be treated, the better the prospect is for a good outcome. If you notice any of the signs indicating a possible infection or inflammation in your pet’s ears or if you notice any changes in your cat's normal head position or movement, a checkup should be scheduled promptly.
Also see professional content regarding otitis media and interna.