Felis ISSN 2398-2950

Otitis media

Synonym(s): Middle ear disease

Contributor(s): Agnes Delauche, Agnes Delauche, Rosanna Marsella, Harry Scott

Introduction

  • Inflammation of the middle ear.
  • Cause: sequel to otitis externa, following iatrogenic damage to tympanum, or in association with neoplasia or inflammatory polyps.
  • Signs: aural pain, otorrhea, head shaking, Horner's syndrome, concurrent labyrinthitis, facial nerve involvement.
  • Diagnosis: history, clinical signs, otoscopy, radiography.
  • Treatment: systemic antibiosis, bulla osteotomy if indicated.
  • Prognosis: good if uncomplicated bacterial infection responsive to antibiosis, guarded if vestibular signs or neoplasia.
    Print off the owner factsheet on Chronic otitis Chronic otitis to give to your client.Follow the diagnostic tree for Evaluating and Managing Otitis Externa Media Evaluating and Managing Otitis Externa Media.

Pathogenesis

Pathophysiology

  • Neoplasia of the external ear or para-aural abscess may lead to secondary otitis media.
  • Occasional sequel to otitis externa Otitis externa, or iatrogenic damage to tympanum during irrigation.
  • Inflammatory polyps Nasopharyngeal polyp commonly cause chronic otitis in the cat but are thought to result from previous episodes of otitis media. Most polyps appear to arise from the auditory tube (Eustachian tube).
  • Otitis media secondary to otitis externa is most likely to occur as a result of neoplasia of the external ear canal and/or para-aural abscessation.
  • The most common cause of chronic otorrhea in the cat is the extension of inflammatory polyps from the middle ear cavity through the tympanum into the horizontal canal.
  • Otitis externa   →   debris accumulation in contact with eardrum   →   eardrum weakened by infection and ruptures   →   medial extension of inflammatory process   →   hyperemia and thickening of mucoperiosteal lining   →   accumulation of exudate in tympanic bulla   →   thickening/sclerosis of bulla   →   medial spread to cause otitis interna or, rarely, bulla osteomyelitis.
  • Iatrogenic damage to tympanum   →   access to middle ear of pathogens   →   inflammatory response   →   otitis interna.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Allgoewer I, Lucas S & Schmitz S A (2000) Magnetic resonance imaging of the normal and diseased feline middle ear. Vet Rad Ultra 41 (5), 413-418 PubMed.
  • Bruyette D S & Lorenz M D (1993) Otitis externa and otitis media: diagnostic and medical aspects. Semin Vet Med Surg (Small Anim) (1), 3-9 PubMed.
  • Trevor P B & Martin R A (1993) Tympanic bulla osteotomy for treatment of middle-ear disease in cats: 19 cases (1984-1991). JAVMA 202 (1), 123-128 PubMed.
  • Boothe H W (1991) Surgery of the tympanic bulla (otitis media and nasopharyngeal polyps). Probl Vet Med (2), 254-269 PubMed.


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