Causes

• Middle ear problems generally consist of infections spreading from the outer to the middle ear. Bacteria or yeast overgrowth usually cause the infection. Rarely, Pet Education reports, "bacterial infections may ascend from the oral cavity through the auditory tube and into the ear."
  
  

Symptoms

• Visible signs of a middle ear infection include excessive scratching and shaking of the head and ears, ear discharge that is sometimes bloody, and pain. Severe middle ear infections can lead to facial paralysis on the side of the infected ear.
  
  

Diagnosis

• The middle ear cannot be seen by the naked eye unless the eardrum is ruptured. Consequently, diagnosis of middle ear infections generally includes anesthetizing the feline so the veterinarian can perform an otoscopic exam and take X-rays.
  
  

Treatment

• Treatments of middle ear infections range from oral antibiotics to surgery. Chronic middle ear infections might require an incision through the eardrum so the middle ear can be flushed. In severe cases, parts of the middle ear might be removed.
  
  

Prevention

• Keeping a cat's ears clean and bacteria-free helps prevent middle ear infections. Apply a veterinary-recommended ear wash, massage it into the ear and remove any discharge with a cotton ball to help prevent middle ear infections.