Animals – Treating ears

Ear infections are one of the most common reasons for pet owners to consult with their vet. The condition becomes apparent when your pet constantly scratches its ears. Head shaking, reddening, scaling and swelling of the externally visible part of the ears are further pointers to an ear infection. The clinical examination will involve the exploration of the ear canal with an otoscope to look at the lining, check for foreign bodies and establish the integrity of the tympanic membrane (ear drum).  

At the same time, a smear is taken for cytology (examination of body cells). The findings from the cytology, in conjunction with the otoscopical examination, will allow the clinician to select a suitable topical medication for treatment. Strict adherence to the treatment protocol will, in the vast majority of cases, lead to rapid relief and disappearance of the symptoms.

However, recurrent ear infections can be more difficult to treat. Underlying causes can result from the activity of the immune system (immune-mediated) or complicated by a ruptured ear drum, together with an infection of the middle ear.

Apart from immune-mediated factors, the most common reason for recurrence of ear infections is non-compliance with the treatment instructions. Sometimes it is very difficult to be compliant. Your dog resists the application of the medication because it is painful. Alternatively, you do not feel confident to deliver the right amount into the ear canal. The upshot is that treatments are often skipped, poorly delivered or shortened.

In addition to complying with the treatment instructions, it is also important that the surface of the ear canal is clean before topical medication is administered – otherwise delivery of sufficient antimicrobial concentration cannot be achieved, and this can lead to resistant bacteria developing within the brown surface sludge, known as biofilm. Sometimes these biofilms have to be flushed out under general anaesthesia and sometimes only systemic antibiotic treatment will reach the site of infection, especially when the ear canal has a fibrotic stenosis (narrowing).  Even after all microbes are dead, inflammation will often persist and systemic glucocorticoids might have to be given for a few weeks.

But do not despair, and do not hesitate to revisit the clinic for progress check-ups. Most importantly, remember why it is so critical to adhere to the initial treatment plan protocol.

Olaf Klein, Wellsford Vet Clinic
www.vetsonline.co.nz/wellsfordvet