Neurological signs in 23 dogs with suspected rostral cerebellar ischaemic stroke

Barbara Thomsen, Laurent Garosi, Geoff Skerritt, Clare Rusbridge, Tim Sparrow, Mette Berendt, Hanne Gredal

In dogs with ischaemic stroke, a very common site of infarction is the cerebellum. The aim of this study was to characterise neurological signs in relation to infarct topography in dogs with suspected cerebellar ischaemic stroke and to report short-term outcome confined to the hospitalisation period. A retrospective multicentre study of dogs with suspected cerebellar ischaemic stroke examined from 2010-2015 at five veterinary referral hospitals was performed. Findings from clinical, neurological, and paraclinical investigations including magnetic resonance imaging were assessed. Twenty-three dogs, 13 females and 10 males with a median age of 8 years and 8 months, were included in the study. The Cavalier King Charles Spaniel (n = 9) was a commonly represented breed. All ischaemic strokes were located to the vascular territory of the rostral cerebellar artery including four extensive and 19 limited occlusions. The most prominent neurological deficits were gait abnormalities (ataxia with hypermetria n = 11, ataxia without hypermetria n = 4, non-ambulatory n = 6), head tilt (n = 13), nystagmus (n = 8), decreased menace response (n = 7), postural reaction deficits (n = 7), and proprioceptive deficits (n = 5). Neurological signs appeared irrespective of the infarct being classified as extensive or limited. All dogs survived and were discharged within 1-10 days of hospitalisation. Dogs affected by rostral cerebellar ischaemic stroke typically present with a collection of neurological deficits characterised by ataxia, head tilt, and nystagmus irrespective of the specific cerebellar infarct topography. In dogs with peracute to acute onset of these neurological deficits, cerebellar ischaemic stroke should be considered an important differential diagnosis, and neuroimaging investigations are indicated. Although dogs are often severely compromised at presentation, short-term prognosis is excellent and rapid clinical improvement may be observed within the first week following the ischaemic stroke.