A Cat's Ears - Inside and Out

Cats are super-hearers.  As they evolved, they had to be in order to survive.  Our cats today hear lower and higher frequencies than people and even dogs can.  Feline ears are also set up to help them with balance, distance perception and coordination.  There are lots of muscles in a cat's ear, enabling them to shift their ears toward a sound - something like radar.  All of this means cats rely a lot on their ears, which is why things go badly wrong when ears develop a problem. 

Like a lot of other mammals, cats' ears have three major areas:  outer ear (pinna and ear canal; middle ear (eardrum and tiny ossicle bones that vibrate); and inner ear (sensory cells and the vestibular system for balance and spacial orientation).  That's all pretty straightforward but what can throw an ear exam off for many vets is that cats have a bony shelf, or septum, that breaks the middle ear into two compartments, hiding the lower portion.  This presence of the septum can hide problems that develop in the middle and inner ear.

Common outer ear problems for cats are bacterial or fungal skin infections, ear mites, mange, foreign bodies, bites or scratches and allergies.  All of these can cause itching, bleeding and other visible signs like scratching or a head tilt.

A cat's inner ear may also develop growths.  The most common of these is polyps.  These non-cancerous growths can appear in the ear canal, in the middle ear or even in the back of a cat's throat.  They are caused by viruses, so cats who are positive for FIV or feline leukemia may be more susceptible to them.  Our blog article on polyps lists symptoms as:  shaking the head, scratching or rubbing the ear, pain when the ear is touched, a bad odor and, in some cases, discharge.  If the polyp and infection are in a cat's inner ear, they may also have a head tilt or frequent shifting of the eyes.  Throat polyps can cause difficulty breathing.  If a cat develops a polyp, as BCR's Popcorn and Candy did, it will likely require surgery to remove it.  How simple the surgery is depends on the polyp's location and how far it has spread.

Growths in the middle and inner ears are more serious and difficult to treat.  Masses and tumors, both benign and malignant, occur more frequently in older cats and can be triggered by long-term infections.  These masses can be much harder to detect and identify until your cat begins to show symptoms like a head tilt, disorientation, and nausea.  To diagnose the problem, your vet may refer you to a veterinary neurologist or surgeon.  To see deeply into a cat's ear they will likely use CT scan or MRI, which requires anesthesia.  At that time they may also get a tissue sample of the tumor to biopsy. 

Depending on what the tests reveal, most tumors must be removed surgically.  While some can be removed using laser surgery, others require more aggressive removal.  If the tumor has damaged the ear canal, the surgeon may recommend a total ear canal ablation, which removes the tumor along with the ear canal and cleans out the inner ear area.  This is considered the most effective treatment.  Additional treatment going forward will depend on the nature of the tumor. 
 
Since early detection of middle and inner ear problems in cats is difficult, making sure your cat has regular ear exams as part of his health routine is important.  If you notice any of the symptoms listed above, go the extra mile to find the source of the problem.

CLICK HERE to read some interesting facts about feline ears.

CLICK HERE to read more about conditions that occur in feline ears.