Page 22 - VetCPD Jnl Volume 7, Issue 4

VETcpd - Dermatology
exudate will enhance the effectiveness
of some antibacterial treatments such
as gentamicin and polymixin B. Ear Cleaners containing TrizEDTA can also potentiate the effect of certain antibiotics such as gentamicin and fluoroquinolones when used as a pre-treatment solution. Care should be taken not to over clean the ear because this can cause irritation and maceration of the ear canal which
in turn delay resolution of the otitis.
It is advisable that ear cleaning is only performed two to three times a week
to prevent maceration of the ear canal. The exception to this rule would be when using TrizEDTA as a pre-treatment solution, which would be used 30 minutes prior to applying the ear drops on every occasion, or when using an acidic ear cleaner alone to manage a Malassezia otitis case.
Owners shoSub
Table 2: Antimicrobial choices depending on the cytology findings
ORGANISM
Coccoid bacteria
Rod shaped bacteria
Yeast (likely Malassezia pachydermatitis)
not usually effective at managing pain
SUITABLE ANTIMICROBIAL CHOICE
First line:
• Florphenicol
• Polymyxin B combined with Miconazole
Second Line:
• Fluoroquinolones
• Gentamicin
• Fluoroquinolones; marbofloxacin, orbifloxacin
• Miconazole
• Clotrimazole • Posaconazole • Terbinafine
uld be warn
contact reactions and asked at re-exam-
ed about po
ssible
in these cases and obviously should not be given with glucocorticoids. Opiate based analgesics can be very helpful in otitis cases and anecdotally good clinical response has been seen with paracetamol- codeine (Pardale V; Dechra) for analgesia.
ers
ination if there have been any problems
with the treatment prescribed.There are a
wide range of ear cleaners on the veterinary
market and most of these do have good
antimicrobial action. Care should be
taken when selecting a product especially 3. Identify the primary cause
pH and the
condition o
will cause the patient discomfort.
In some cases of otitis externa an ear flush under general anaesthetic may be appropriate to help clean the ear canal and remove debris. It is important to realise that there is generally no rush
to perform an ear flush and most cases will benefit from a 7 - 10 day course of prednisolone (0.5-1mg/kg once daily) prior to the ear flush as this will reduce the inflammation present and make the process of flushing more easily achieved.
2. Reduce inflammation
and pain
Glucocorticoids such as prednisolone used at a dose of 0.5-1mg/kg orally once daily are useful to reduce inflammation in the ear canal when managing
cases of otitis externa. Reducing the inflammation present also helps change the conditions within the ear canal. However, it should be noted that steroids are not analgesics although they may make the dog more comfortable by reducing the inflammation.
Otitis externa is a painful condition and so consideration should be given to providing analgesia for these cases. Non-steroidal anti-inflammatories are
Page 20 - VETcpd - Vol 7 - Issue 4
of an underlying allergic skin disease should be considered and investigated. This would include performing a dietary trial to assess what role if any diet is playing in the skin disease and possibly allergen testing if appropriate.
Figure 6: This is an example of an end stage ear where the proliferative tissue has completely occluded the external ear canal.
important to assess whether the client can apply the treatment and to take this into consideration when the medication is dispensed. Sometimes providing
a syringe for the client to apply ear medication/cleaner can be useful and seems to aid compliance. Demonstrating to your clients how to apply ear drops and cleaner is also useful.
Managing clients’ expectations is vital. It is advisable, at an early stage, to tell clients of recurrent otitis cases that there is likely to be an underlying cause.
Why do cases recur or relapse?
There are many reasons why cases can relapse. Some of the common reasons include:
• Discontinuing treatment too early.
• The primary, predisposing or perpetuating factors have not been addressed.
f the It i
s importa
nt that the
primar
y caus
e of
regarding its
ear canal, for example extremely acid or the otitis is addressed. If the dog has had alkaline products in an ulcerative ear canal recurrent episodes of otitis the possibility
scrib
Only
Any primary, predisposing or perpetuating factors need to be managed. Regular ear cleaning can be useful
to prevent a relapse of otitis in some cases. Bear in mind that if the otitis has been severe it may take many months
of recovery of the normal ear cleaning mechanisms and so ear cleaning may need to be continued for many months once the infection has resolved.
In cases where an underlying allergic skin disease is identified this will need to be managed appropriately and sometimes the use of topical steroids in products such as Recicort; Dechra may be useful.
Potential management problems
Cases of otitis externa can be frustrating for clients as they may have a protracted treatment course and often dogs are resistant to application of ear drops which in turn can affect owner compliance and therefore the treatment outcome. It is
4. Prevent a recurrence of otitis