Page 19 - VetCPD Jnl Volume 7, Issue 4

What clinical signs are
seen in cases of otitis?
• Head shaking
• Ear scratching
• Erythema of the pinna, which may also be associated with hyperpigmentation and lichenification depending on chronicity (Figure 1)
• Abnormal ear carriage - for example usually pricked ears may be dropped.
• Head tilt
• Pain/discomfort
• Odour
• Discharge from the ears.This can be varied in its appearance: yellow, green, brown, waxy, purulent (Figure 2)
VETcpd - Dermatology Table 1: Microorganisms most commonly identified
in cases of otitis externa in the dog
Staphylococcus pseudintermedius Staphylococcus aureus Streptococcus
Enterococcus
E. coli
Proteus spp. Pseudomonas spp. Klebsiella spp. Cornyebacterium spp.
Malassezia pachydermatitis (Candida spp.)
COCCOID BACTERIA
ROD SHAPED BACTERIA
YEAST
• If otitis media is present you may also notice some neurological signs such as head tilt, facial paralysis, ataxia, difficulty chewing or opening the mouth (client may have noticed)
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General approach to
cases of otitis in practice
History
It is important with any dermatological
case to get a thorough history. Some
questions that may be especially relevant Figure 1: In this image you can appreciate the Figure 2: This dog has a brown purulent discharge when dealing with a case of otitis would erythema and lichenification of the pinna which is also from its ear.
include:
associated with hyperpigmentation in some areas.
• Signalment: this is often known before we even see the patient and
can be useful as some breeds are predisposed to certain conditions which may make the development
of otitis more likely. For example, Labradors,West Highland White Terriers and Staffordshire Bull Terriers are predisposed to atopic dermatitis which may be a primary cause of recurrent otitis (Jaeger et al. 2010). The age of the patient may also give us important clues to the underlying cause of the otitis for example: puppies are more likely to have Otodectes,
but if an older patient has suddenly presented with recurrent episodes
of otitis then the possibility of an underlying endocrinopathy causing immunosuppression should be considered.Whereas recurrent otitis in a younger dog may be more likely to have an allergic aetiology.
• Management and lifestyle: it is useful to ask questions relating to the patient’s lifestyle and general health. For example, if a dog swims regularly, this would be a predisposing factor for the otitis. Another example would be
if the client reported polydipsia and polyuria which could be clinical signs of an underlying endocrine disease which can be a primary cause of otitis.
clinical signs are present the possibility of otitis media needs to be considered.
General physical examination
This should be performed in all patients and the whole dog should be examined. As already discussed, we should ensure there are no obvious neurological
signs, such as head tilt or facial paralysis which would lead you to suspect otitis media where topical treatment may be contraindicated.
Dermatological examination
Identifying any other skin lesions that may be present may help us to identify if there is a more generalized skin disease present. Examination of the ears is ideally performed at the end of the examination as often they are painful, and the patient resents this part of the examination. Palpation of the auricular cartilages can be useful to appreciate any thickening of the ear canal, which can be observed in patients with a chronic history of otitis. The pinna should be visually inspected along with the external auditory meatus, any erythema or ulceration should be noted, along with any discharge or odour.
• Clinical signs: the onset of the otitis Only
can give us important clues to the underlying cause for example: sudden onset of clinical signs after running through a field of grass may raise the index of suspicion for a foreign body. The more typical history in most cases of otitis is an insidious onset of disease. If the condition is bilateral it would make a foreign body less likely as a cause for the otitis.
• Previous history of otitis: If the patient has a previous history of otitis an underlying allergic aetiology would be more likely.The index of suspicion for atopic dermatitis would also be increased in a case with a seasonal pattern to their otitis or in a dog with other clinical signs of skin disease such as pedal or generalized pruritus.
• Are there any neurological signs?
It is important in any case of otitis to assess if there are any neurological signs or pain on opening the mouth. If these
VETcpd - Vol 7 Issue 4 - Page 17