Canis ISSN: 2398-2942

Otitis interna

Synonym(s): Inner ear disease, labyrinthitis

Contributor(s): Kyle Braund

Introduction

  • Cause: infection via middle ear or through hematogenous spread.
  • Signs: head tilt, circling and nystagmus (vestibular syndrome).
  • Deafness and disturbances of balance occur together.
  • Facial nerve and sympathetic trunk can be involved in middle ear. Virtually always unilateral.
  • Important to differentiate this disorder from central vestibular disturbances.
    Print off the owner factsheet on Chronic otitis to give to your client.

Pathogenesis

Etiology

  • Extension of opportunistic infection by Staphylococcusspp Staphylococcus spp ,Streptococcusspp Streptococcus sppMalassezia,Clostridium welchii and (especially) Pseudomonas aeruginosa Pseudomonas aeruginosa.
  • Iatrogenic: trauma due to excessive pressure from overzealous irrigation or use of ototoxic compounds in irrigating middle ear.
  • Idiopathic form: hematogenous spread of infectious agent, possibly viral.
  • Trauma to head (rare).

Predisposing factors

General

Specific

Pathophysiology

  • Trigger factor usually unilateral spread of otitis media through round cochlear window to inner ear → in process facial nerve and sympathetic trunk to eye may be damaged → facial paralysis and partial or complete Horner's syndrome on affected side → loss of function of cochlea and semicircular canals → unilateral deafness and disturbance of balance.
Other trigger factors
  • Direct hematogenous infection of inner ear.
  • Iatrogenic damage during treatment of otitis media, through overzealous irrigation or use of ototoxic compounds for irrigation.
  • Head trauma → damage to round cochlear window → leakage of perilymph from semicircular canals.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Garosi L S et al (2001) Results of magnetic resonance imaging in dogs with vestibular disorders - 85 cases (1996-1999)JAVMA 218 (3), 385-391 PubMed.
  • Dvir E et al (2000) Magnetic resonance imaging of otitis media in a dog. Vet Radiol 41 (1), 46-49 PubMed.

Other sources of information

  • Rosychuk R A Wet al(2000)diseases of the ear.In:Textbook of Veterinary Internal Medicine.5th edn. Eds: S J Ettinger & E C Feldman. Philadelphia: W B Saunders. pp 986-1002.


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