Contributors: Kyle Braund

 Species: Canine   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading


  • 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.

Presenting Signs

  • Vestibular syndrome.
  • General dullness and inappetence.
  • Unilateral facial paralysis.
  • Rolling and falling towards affected side.
  • Hemifacial spasm on affected side.

Breed Predisposition

  • Breeds prone to otitis externa, eg Spaniels.



  • 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




  • 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.


Presenting Problems

  • Vestibular syndrome.

Client History

  • Concurrent long-term otitis externa Skin: otitis externa.
  • Concurrent otitis media Otitis media.
  • Recent treatment of otitis by instilling potentially ototoxic agents into ear.
  • Recent bulla irrigation or bulla osteotomy Bulla osteotomy.
  • Head tilt.
  • Vomiting.
  • Circling.
  • Head trauma.
  • Seizures.

Clinical Signs

  • Head tilt, affected side down.
  • Circling towards affected side.
  • Nystagmus, fast component away from affected side.
  • Stagger towards affected side.
  • Unilateral deafness present, but only detectable with sophisticated audiological tests.
  • General dullness and inappetence
  • Unilateral facial paralysis, involving upper and lower face.
  • Rolling and falling in direction of lesion.
  • Partial or complete Horner's syndrome: miosis (small pupil), slight ptosis (drooping upper eyelid), enopthalmos (sunken eye), protrusion of third eyelid, conjunctival flare.
  • Bilateral otitis interna.
  • Hemifacial spasm on affected side.
Auroscopic examinationFull neurological examination
  • Findings if central vestibular involvement:
    • Abnormal function of cranial nerve V (trigeminal) - sensory to face; cranial nerve VI (abducens) - eye position → downward strabismus (squint); cranial nerve IX (glossopharyngeal) - gag response; cranial nerve X (vagus) - vocal capacity; cranial nerve XII (hypoglossal) - lingual function.
    • Deficits in hopping and placing responses.
    • When held up, dog's body turned towards side of lesion.
    • Unilateral hypermetria.
    • History of recent onset of seizures.

Diagnostic Investigation

  • To diagnose chronic otitis media Otitis media.
  • Absence of normal air shadow in tympanic bulla.
  • Diffuse thickening of bulla wall.
  • Bony destruction and gross bony proliferative changes in the bulla.
  • Gross bony proliferative changes with involvement of the temporomandibular joint.
  • Examination under anaesthesia:
  • Eardrum rupture identified by palpation with blunt needle or probe Otitis media.
  • Eustachian tube not patent Otitis media.
    Only test for Eustachian tube patency when a cuffed endotrachial tube is in place.
  • Caloric stimulation:
  • When otitis interna present, no nystagmus initiated by irrigating external ear canal with warm or cold water.
  • Microbiology:
  • Bacteriology and sensitivity of aural discharge: mixed infection, including yeasts, susceptible to broad-spectrum antibiotics or polypharmaceutical preparations.

Differential Diagnosis

Peripheral vestibular syndromeVestibular syndrome with additional central nervous system signs


Standard Treatment

  • All of: Broad-spectrum, bacteriocidal antibiosis.
  • and: Oral corticosteroids.
  • and: Bulla osteotomy with bulla irrigation if evidence of otitis media Otitis media.
Vestibular osteotomy if marked tissue changes in tympanic bulla, eg granulation tissue or bony proliferation.


Subsequent Management


  • Neurological re-examination.



  • Reasonable.

Expected Response to Treatment

  • Neurological signs resolve over a long time period (months) if effective treatment given.
  • Head tilt may be permanent.

Reasons for Treatment Failure

Further Reading


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.

Other Sources of Information