MRI findings in a dog with otitis media and suspected otitis interna

Garosi LS, Lamb CR, Targett MP. 

Vet Rec 2000;146:501-502.

The clinical signs of otitis interna in the dog and cat are usually those of a peripheral vestibular syndrome,which reflects injury to the vestibular nerve or receptor organs(DeLahunta 1983).Clinical signs may,therefore,include head tilt,falling,rolling,circling,nystagmus,strabismus,andasymmetric ataxia in the presence of normal mental status and normal postural reaction (De Lahunta 1983, Shell 1988, Oliver 1990,Braund 1994) Many diagnostic tests used or the evaluation of vestibular disorders, such as neurological examination, cerebrospinal fluid analysis and brainstem auditory-evoked potentials, are insensitive and non-specific (Bailey and Higgins 1986, Shell 1988, Sims and Moore 1988, Strain 1992). Otitis interna does not usually produce radiographic signs and hence the diagnosis is usually based on clinical signs and radiographic evidence of associated otitis media (Shell 1988). However, negative radiographs do not rule out the possibility of middle ear disease; 25 per cent of dogs with otitis media have no radiographic changes (Remedios and others 1991). Computed x-ray tomography is a more sensi- tive test for the detection of otitis media (Love and others 1995), and the use of magnetic resonance imaging (MRI) for the investigation of canine middle ear disease has been described recently (Forrest 1999).