ACCREDITED CPD - DERMATOLOGY
casionally sedatives may be necessary until the pet
has become accustomed to the procedure.
and excessive cerumen may prevent medications
from reaching the epithelium.
The pet should be suitably restrained, as this allows
for speedy instillation of otic products. For dogs, restraint may include a muzzle and cats may need to
be wrapped in a towel. The author advises that dogs
and cats should be accustomed to a collar, and dogs
should have the lead attached while the ears are treated. Dogs should be trained to sit during application
of otic products.
Thick, dry, or waxy material requires a ceruminolytic
solution such as carbamide peroxide, dioctyl sodium
sulfosuccinate (DSS) or combinations of weak acids.
If the tympanic membrane is ruptured, detergents and
DSS are contraindicated; milder cleansers (eg, saline,
saline plus povidone iodine, the Triz EDTA formulation)
should be used to flush the ear.
A treat given afterwards encourages compliance. Pets
may want to irritate (rub or scratch at) the ear and if
a collar and lead has been applied they can be taken
for a walk immediately afterwards as a distraction and
reward for compliance.
Rinsing products should be inserted by holding the
container vertical and upside down. The owner holds
the ear pinnae with one hand, and the solution is instilled along the grooves of the inner pinnal surface
into the canal. This avoids the container tip contacting an inflamed ear.
The owner maintains their hold on the ear pinna to
prevent the pet shaking the product out of the canal, and gently massages the base of the ear canal
to promote the action. Cotton wool or tissue paper
can be used to wipe away excess solution since cats,
especially, are averse to topically applied liquids. The
owner may not be 100% successful at first, but should
be encouraged to persist on a regular basis.
Discuss with the owner the suspected cause of the
otitis, emphasising that treatment should be long
term or even lifelong. All primary and secondary
causes and predisposing factors should be identified
and managed. Pain or pruritus should be controlled.
Otitis externa is one of the few dermatologic conditions in which glucocorticoids concurrently with antimicrobial use are beneficial. Glucocorticoids such
as prednisolone and triamcinolone decrease swelling
of the ear canal - a key to successful treatment.
Duration depends on the severity. Ear hygiene is important; in particular, the hair in the peri-auricular area
should be clipped as well as hair on the inner surface
of the pinnae. This facilitates cleaning and medication. Plucking hair from the canal is controversial but
may be necessary, under anaesthesia, to adequately
resolve the infection.
The first ear cleaning should be performed in the clinic, and owners should refrain from topical administration until rechecked in 5–7 days since they may be
too aggressive, causing further damage. Owners can
administer systemic drugs and then begin to clean the
ears after the first recheck, provided the otitis is resolving. Topical medications are inactivated by exudates,
Effective treatment may require both topical and systemic antimicrobial therapy, along with pain medications and glucocorticoids. In the management of
acute bacterial otitis, the administration of corticosteroids in combination with antibacterial agents causes
as reduction in exudation, pain, swelling, and glandular secretions. The least potent glucocorticoid at the
lowest effective dose should be used.
Most topical products contain a combination of an antibiotic or antifungal and glucocorticoids. Most dogs
require the instillation of at least one ml twice daily
for effective therapy. Products with an aqueous base
are preferable, however, vinegar dilutions and propylene glycol should be used with caution since swelling
of the lining of the ear canal and increased glandular
secretions may result. Substances that do not usually irritate the normal ear may result in irritation and
inflammation.
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