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| ==Aetiology== | | ==Aetiology== |
| There are three areas which regroup the causes of otitis externa. | | There are three areas which regroup the causes of otitis externa. |
− | | + | :'''Predisposing factors''' increase the risk of development of the disease. |
− | '''Predisposing factors''' increase the risk of development of the disease. | + | :'''Primary factors''' directly cause the otitis. |
− | | + | :'''Perpetuating factors''' prevent the resolution of otitis externa once it develops. |
− | '''Primary factors''' directly cause the otitis. | |
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− | '''Perpetuating factors''' prevent the resolution of otitis externa once it develops. | |
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| ===Predisposing factors=== | | ===Predisposing factors=== |
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| ===Primary factors=== | | ===Primary factors=== |
− | <u>Parasites</u>: ''[[Otodectes cynotis]]'', ''Sarcoptes'', ''Demodex'', ''Neotrombicula'', ticks | + | <u>Parasites</u>: ''[[Otodectes cynotis]]'', ''[[Sarcoptes]]'', ''[[Demodex]]'', [[Trombicula autumnalis|''Neotrombicula'']], [[:Category:Ticks|ticks]] |
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− | <u>Fungi</u>: Dermatophytosis | + | <u>Fungi</u>: [[Dermatophytosis]] |
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− | <u>Allergies</u>: atopic dermatitis, diet, contact | + | <u>Allergies</u>: [[Atopic Dermatitis|atopic dermatitis]], diet, [[Contact Dermatitis|contact]] |
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| <u>Foreign bodies</u>: grass seeds, grass awns, | | <u>Foreign bodies</u>: grass seeds, grass awns, |
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− | <u>Abnormal epidermal turnover or sebum production</u>: [[Seborrhea|seborrhea]], endocrinopathy, nutritional problems, sebaceous adenitis | + | <u>Abnormal epidermal turnover or sebum production</u>: [[Seborrhea|seborrhea]], endocrinopathy, nutritional problems, [[Sebaceous Adenitis|sebaceous adenitis]] |
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| <u>Primary keratinisation defects</u>: [[Seborrhea|idiopathic seborrhoea]] | | <u>Primary keratinisation defects</u>: [[Seborrhea|idiopathic seborrhoea]] |
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− | <u>Autoimmune disease</u>: pemphigus foliaceus | + | <u>Autoimmune disease</u>: [[Pemphigus Foliaceus|pemphigus foliaceus]] |
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− | <u>Miscellaneous</u>: juvenile cellulitis | + | <u>Miscellaneous</u>: [[Juvenile Pyoderma|juvenile cellulitis]] |
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| ===Perpetuating factors=== | | ===Perpetuating factors=== |
− | <u>Bacteria</u>: ''S. intermedius'', ''Pseudomonas aeruginosa'', ''Proteus'' | + | <u>Bacteria</u>: ''S. intermedius'', ''[[Pseudomonas aeruginosa]]'', ''[[Proteus]]'' |
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− | <u>Fungi</u>: ''Malassezia pachydermatis | + | <u>Fungi</u>: ''[[Malassezia pachydermatis]] |
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− | <u>Topical treatments</u>: innapropriate use of topical treatments | + | <u>Topical treatments</u>: inappropriate use of topical treatments |
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| <u>Progressive ear pathology</u>: ulceration, glandular hypertrophy and atrophy, thickened, folded canals | | <u>Progressive ear pathology</u>: ulceration, glandular hypertrophy and atrophy, thickened, folded canals |
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| <u>Otitis media</u> | | <u>Otitis media</u> |
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− | ==Clinical signs== | + | ==Clinical Signs== |
| The animal will present with a history of '''head-shaking and ear scratching''', either acute-onset and severe or chronic and intermittent. | | The animal will present with a history of '''head-shaking and ear scratching''', either acute-onset and severe or chronic and intermittent. |
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| The ears may show evidence of '''self-trauma, erythema, and primary and secondary lesions'''. There may be pinnal deformities and the ear canal may feel thickened on palpation. | | The ears may show evidence of '''self-trauma, erythema, and primary and secondary lesions'''. There may be pinnal deformities and the ear canal may feel thickened on palpation. |
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− | The animal may present with an '''aural haematoma''' from head-shaking if it is severe. | + | The animal may present with an [[Aural Haematoma|'''aural haematoma''']] from head-shaking if it is severe. |
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| There may be '''discharge''' coming from the ear which may be brown and waxy or purulent and green. | | There may be '''discharge''' coming from the ear which may be brown and waxy or purulent and green. |
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| '''Medical therapy''' may be useful: | | '''Medical therapy''' may be useful: |
− | | + | :'''Oral corticosteroids''' can be given for a short period at a high dose to open constricted canals and improve topical treatment efficacy. |
− | '''Oral corticosteroids''' can be given for a short period at a high dose to open constricted canals and improve topical treatment efficacy. | + | :If there is a bacterial otitis, '''oral antibiotics''' are useful. |
− | | + | :If ''[[Otodectes cynotis]]'' is detected, a general topical or systemic '''antiparasitic''' is indicated as this parasite can invade sites other than the ear. |
− | If there is a bacterial otitis, '''oral antibiotics''' are useful. | + | :Many '''topical treatments''' are available for otitis externa cases. These usually provide a '''combination''' of anti-bacterial, anti-fungal, anti-parasitic and anti-inflammatory agents. |
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− | If ''Otodectes cynotis'' is detected, a general topical or systemic '''antiparasitic''' is indicated as this parasite can invade sites other than the ear. | |
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− | Many '''topical treatments''' are available for otitis externa cases. These usually provide a '''combination''' of anti-bacterial, anti-fungal, anti-parasitic and anti-inflammatory agents. | |
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| Duration of treatment should continue until the infection is resolved. | | Duration of treatment should continue until the infection is resolved. |
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− | Animals should be examined and '''cytology swabs taken every week''' until there is no cytological evidence of infection. | + | Animals should be examined and '''cytology swabs taken every week''' until there is no cytological evidence of infection. This usually takes '''2-4 weeks''' for acute cases. Chronic cases may take months to resolve and therapy may have to continue for the rest of the animal's life. |
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− | This usually takes '''2-4 weeks''' for acute cases. | |
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− | Chronic cases may take months to resolve and therapy may have to continue for the rest of the animal's life. | |
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| <u>Prevention:</u> | | <u>Prevention:</u> |
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| '''Palpation''' of the ear canals and '''radiographs''' will help determine if there are chronic changes to the ear canals such as calcification. | | '''Palpation''' of the ear canals and '''radiographs''' will help determine if there are chronic changes to the ear canals such as calcification. |
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− | ===Lateral wall resection=== | + | ===Lateral Wall Resection=== |
| This can be performed at an early stage to increased '''drainage and ventilation''' of the external ear canal. | | This can be performed at an early stage to increased '''drainage and ventilation''' of the external ear canal. |
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| Harvey, R. (2001) '''Ear diseases of the dog and cat''' ''Manson Publishing'' | | Harvey, R. (2001) '''Ear diseases of the dog and cat''' ''Manson Publishing'' |
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− | [[Category:To Do - Helen]]
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− | [[Category:To Do - Review]]
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| {{review}} | | {{review}} |