Contributors: Agnes Delauche, Rosanna Marsella, Harry Scott, Sue Paterson
Species: Feline | Classification: Diseases
- Infection involving the organs of hearing and balance housed within the bony labyrinth.
- Cause: most commonly spread of infection from middle ear, also hematogenous route or ascending infection through the Eustachian tube.
- Signs: head tilt, circling and nystagmus (vestibular syndrome); unilateral deafness.
- Diagnosis: history, clinical signs, neurological assessment, advanced diagnostic imaging (MRI, CT).
- Treatment: broad-spectrum antibiotics initially, then based on cytology and bacterial culture of material collected on myringotomy where possible.
- Prognosis: good but high frequency of residual deficits.
Print off the owner factsheet on Chronic otitis to give to your client.
- Vestibular syndrome Vestibular disease (loss of balance, ataxia Ataxia, nystagmus, strabismus).
- Vomiting Vomiting.
- General listlessness and inappetence.
- Deafness Deafness: acquired (unilateral so may be directional).
- Concurrent otitis media Otitis media:
- Extension of opportunistic infection from otitis media/externa.
- Hematogenous spread.
Inner ear disease
- Damage to cochlea:
- Sensory nerve endings within the cochlea damaged by infection/trauma/ototoxicity leading to deafness.
- Damage to vestibular apparatus:
- Vestibular system consists of proprioceptors (saccule, utricle and semicircular canals) within the inner ear (petrosal temporal bone), the vestibular nerve (VIII), four brainstem nuclei and the cerebellum. Peripheral vestibular dysfunction (PVD) is as a result of damage to structures with the petrosal temporal bone. Central vestibular dysfunction (CVD) is due to damage to structures in the brain stem and cerebellum.
- PVD most commonly extension of otitis externa/otitis media or idiopathic vestibular syndrome (IVS).
- CVD most commonly caused by neoplasia, inflammatory or infectious disease, thiamine deficiency Thiamine deficiency, vascular, traumatic or toxic conditions.
- Vestibular syndrome.
- Otitis interna usually presents with signs of PVD.
- Head tilt, affected side down .
- Circling towards affected side.
- Horizontal nystagmus, fast component away from affected side and not affected with head position.
- Rolling/falling to affected side.
- Unilateral deafness present Deafness: acquired, detectable by Brainstem auditory evoked response (BAER) testing in specialist center Hearing tests.
- Positional ventral strabismus in ipsilateral eye.
- Vomiting Vomiting.
- Concurrent otitis media Otitis media.
- General dullness and inappetence.
- Unilateral facial paralysis Facial nerve neuropathy, involving upper and lower face but only with concurrent otitis media.
- Horner's syndrome Horner's syndrome .
- Neurological assessment Neurological examination:
- Necessary to differentiate from CVD.
- Head tilt.
- Ataxia Ataxia.
- Horizontal nystagmus with quick phase away from side of lesion. With central lesions, positional and vertical nystagmus may be present, ie direction is altered with head position.
- With central vestibular lesions, paresis and reduction or absence of proprioception can occur in the ipsilateral limbs. There may also be evidence of multiple cranial nerve involvement.
- Otoscopic examination:
- Concurrent otitis media/externa where disease has developed from ear disease.
- Brainstem auditory-evoked response (BAER):
- Evidence of hearing loss.
- Computed tomography Computed tomography: head:
- More sensitive for investigation of middle and inner ear disease than radiography.
- Magnetic resonance imaging Magnetic resonance imaging: basic principles:
- Considered the imaging test of choice to investigate intracranial cases of vestibular dysfunction and inner ear disease.
Peripheral vestibular syndrome
- Congenital vestibular disease Vestibular disease.
- Idiopathic feline vestibular syndrome Vestibular disease.
- Neoplasia of petrous temporal bone or vestibular nerve.
- Nasopharyngeal polyps Nasopharyngeal polyp.
Central vestibular syndrome
Initial Symptomatic Treatment
- Broad-spectrum antibiotics Therapeutics: antimicrobial drug initially but where possible they should be based on cytology, and culture and sensitivity of material collected from the middle ear by myringotomy Myringotomy. Drugs needed for 6-8 weeks in chronic cases.
- See also ear therapeutics Therapeutics: ear.
All of Broad-spectrum, bacteriocidal antibiosis Therapeutics: antimicrobial drug Therapeutics: ear.
And Ventral bulla osteotomy Bulla osteotomy with bulla irrigation, if evidence of unresponsive otitis media.
- Gradual resolution of neurological deficits, (balance, circling, nystagmus).
In many cases the neurological deficits are irreversible but compensation occurs for the vestibular deficits.
- Resolution of signs of otitis media.
- Neurological re-examination.
- Good in straightforward cases of otitis interna/labyrinthitis. Damage to delicate nerve endings is likely to be irreparable but disease is rarely bilateral, so some degree of compensation occurs; however, facial paralysis is usually irreversible.
Expected Response to Treatment
- Neurological signs resolve over a long time period (months).
- Head tilt may be permanent.
Reasons for Treatment Failure
- Recent references from PubMed and VetMedResource.
- Negrin A, Cherubini G B & Platt S (2010) Clinical signs, magnetic resonance imaging findings and outcomes in 77 cats with vestibular disease: a retrospective study journal of feline medicine and surgery. J Feline Med Surg 12 (4), 291-299 PubMed.
- Bischoff M G & Kneller S K (2004) Diagnostic imaging of the canine and feline ear. Vet Clin North Am Small Anim Pract 34 (2), 437-458 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 Jr. (1988) Surgical management of otitis media and otitis interna. Vet Clin North Am Small Anim Pract 18 (4), 901-911 PubMed.
- Schunk K L (1988) Disorders of the vestibular system. Vet Clin North Am Small Anim Pract 18 (3), 641-665 PubMed.
- Shell L G (1988) Otitis media and otitis interna - etiology, diagnosis, and medical management. Vet clin North Am Small Anim Pract 18 (4), 885-899 PubMed.