ACCREDITED CPD - DERMATOLOGY
Aminoglycoside and fluoroquinolone antibiotics
should not be used unless absolutely required for successful treatment but are the most common ingredients in topical otic medications. Because many topical products contain a combination of glucocorticoid,
antibiotic, and antifungal medications, it is imperative
to educate the owner on the frequency and duration
of administration.
Polymyxin B and fluoroquinolone antibiotics have
shown the best success in controlling Pseudomonas
infections in cases in which resistance has been identified through culture. Methicillin-resistant Staphylococcus pseudintermedius and Pseudomonas aeruginosa have emerged as frustrating causes of otitis and
resistance is developing to fluoroquinolones.
Duration of treatment will vary depending on the individual case but should continue until the infection is
resolved based on re-examination and repeat cytology and culture. Animals with bacterial and yeast infections should be physically examined, with roll smears
examined every other week until there is no evidence
of infection. In some chronic cases a therapeutic
regimen must be continued indefinitely.
Infections are often chronic in course and associated
with marked suppurative exudation, severe epithelial
ulceration, pain, and oedema.
Successful treatment is multifaceted and should include the following steps:
1. Identify the primary cause of the otitis and manage it.
2. Remove the exudate via irrigation of the ear canal
3. Identify and treat concurrent otitis media.
4. Select an appropriate antibiotic from the results
of culture and mean inhibitory concentration and
use it at an effective dosage for an appropriate duration.
5. Treat topically and systemically until the infection
resolves (weeks to months).
Non-responsive cases may require surgery. Lateral ear
canal resection may be necessary to allow resection
of neoplasia or polyps, and may assist in hyperplasia of
vertical canal, also known as proliferative otitis externa
(Fig 5.).
Summary
The keys to successful management of chronic otitis
externa include early recognition and management of
of predisposing factors, client education, and the formulation of a consistent management regime. Regular re-evaluation by the veterinary surgeon is essential
to prevent hyperplasia of the ear canal, also known as
proliferative otitis externa.
References
• Disease of the eyelids, claws, anal sacs and ears. In: Muller & Kirk’s
Small Animal Dermatology 2013 eds. Miller W H, Griffin C E, Campbell
K L. Elsevier: 724 – 773
• Norström M, Sunde M, Tharaldsen H, et al 2009 Antimicrobial resistance in Staphylococcus pseudintermedius in the Norwegian dog
population. Microbial Drug Resistance 15(1):55-9.
Figure 5. Chronic hyperplastic changes of the external ear
canal. Surgery is now the only option
Shaping the future of animal health
Accredited CPD
ANSWER the questions on the Vet360 App. Available from the Itunes/Play store!
Use your App to answer the questions. If you want to use the SMS system or the web interface on your PC,
please visit the CPD electronic platform at www.onlinevets.co.za Use the following codes for the SMS system:
9. Otitis Externa. Dr Martin Briggs. SMS code = a22785
8. Canine Idiopathic Dilated Cardiomyopathy. Dr Alain Carter. SMS code = SMS code = a68068
7. Cushings. Various Authors. SMS code = a20643
6. Cyclosporine in Canine Atopy. Dr Heidi Schroeder. SMS code = a24438
5. Management of Diabetes Mellitus Dr Marlies Bohm. a55046
4. Transfusion Medicine in Small Animal Practice. Dr Liesel van der Merwe SMS code = a90559
3. Diagnosis of Demodicosis in Dogs & Cats. Karen A. Moriello SMS code = a22801
2. A review of sterilisation practices and impact on the individual animal, in dogs and cats. Drs K de Cramer
and K May SMS code = a26581
1. Rehabilitation of neurological patients. Dr Megan Kelly, SMS code = a97907
vet360
Issue 02 | APRIL 2016 | 24
April 2016 Vet360 for Madaleen Review.indd 24
2016/03/24 2:24 PM