Failure to detect and treat inflammation within the external ear canal early enough can lead to the establishment of a bacterial infection within the ear.
Often, these infections result when the harmless bacteria that normally inhabit the ear are overwhelmed by the inflammation, allowing their not-so-peaceful counterparts to proliferate and take over.
A creamy brown to yellow discharge carrying a foul odor is characteristic of a bacterial disorder within the ear. Bacterial infections can even be found together with yeast infections within the same ear(s), leading to a discharge having characteristics of both types.
If not treated promptly and vigorously, bacterial infections can become firmly entrenched within the ear canal, making a complete cure difficult. For this reason, veterinary practitioners rely heavily on bacterial cultures and sensitivity tests to tell them which bacteria are involved and which antibiotics will be most effective.
Otic preparations containing appropriate antibiotics, often combined with anti-inflammatory medications, are used to combat cases of bacterial otitis externa. Bacteria within the ear have been effectively treated with 5% vinegar (acetic acid) solutions.
If a ruptured eardrum is suspected, selection of treatment agents must be done carefully. For example, antibiotics belonging to the class known as aminoglycosides (examples include gentamycin and neomycin) should not be used in the ear directly, since they can cause nerve deafness if exposed to the inner ear.
The same holds true for astringent preparations and acetic acid solutions. In addition, if a ruptured eardrum is suspected, only water-soluble treatment solutions should be used. Ointments should be avoided, as they can become entrapped within the middle ear.
In especially severe cases of bacterial otitis, oral antibiotics might be given concurrently with topical ear medications to afford faster results.