Vestibular syndrome in dogs

Vestibular dysfunction can be central or peripheral. It is relatively common in dogs and there are multiple causes. This retrospective study aimed to assess the frequency of the different etiologies of Peripheral Vestibular Syndrome (PVS) in dogs and collect data about the long-term outcome of these patients.
The sample in this investigation consisted of 188 patients, 73 females and 115 males, with variable ages. The most represented breed was Cavalier King Charles spaniel (20%) and most of the dogs presented an acute onset of the clinical signs. Only 12.7% had history of previous vestibular-related signs.
Head tilt was the most frequent persisting clinical sign and only resolved in two thirds of the patients. Ataxia, facial paralysis, nystagmus, and positional strabismus were also described in the majority of the evaluated dogs.
Magnetic resonance images were obtained from all patients and revealed no abnormalities in 45.2% of the cases; in those where there were findings, facial and vestibulocochlear enhancement were the most frequent. Thyroid function and cerebrospinal fluid analysis were also performed, in 63.3% and 53.7% of the dogs, respectively.
In this retrospective study, idiopathic vestibular syndrome (IVS) was the most common case of PVS, in opposite to previous studies, where otitis media/interna was the most described etiology. Nevertheless, there are significant differences between both studies which can explain this disparity, namely the non-use of advanced imaging modalities in the older investigation.
The cause for IVS is still unknown but it is hypothesized that there is more than one underlying cause for the signs. Prognosis was associated with the history of previous episodes and the finding of cranial nerve enhancement on MRI, being latter linked to artial recovery.

Orlandi R, Gutierrez-Quintana R, Carletti B, Cooper C, Brocal J, Silva S, Gonçalves R. Clinical signs, MRI findings and outcome in dogs with peripheral vestibular disease: a retrospective study. BMC Vet Res. 2020 May 25;16(1):159. doi: 10.1186/s12917-020-02366-8. PMID: 32450859; PMCID: PMC7249679.