Review: spinal shock, crossed extensor reflex, and mass reflex in dogs and cats—a literature review, clinical observations and considerations

The phenomena of spinal shock, crossed extensor reflex, and mass reflex are discussed to different extents in veterinary neurology textbooks, in literature on experimental animal models, and clinical reports on veterinary neurological patients. Aspects related to timing of onset of spinal pathology, their implications for neuroanatomical localizations, and their prognostic significance are clinically relevant. In this review article, the authors discuss and summarize the current literature and highlight collective observations in clinical veterinary neurology patients. Underreported observations emphasized in this article include the possibility of (1) asymmetrical/lateralized/unilateral spinal shock, (2) crossed extensor and mass reflexes in patients with (per-) acute myelopathies, (3) asymmetrical/lateralized/unilateral crossed extensor reflex, (4) mass reflexes observed in patients with (per-)acute myelopathies and concurrently with signs of spinal shock, and (5) a pelvic limb crossed extensor reflex in patients with pathology other than cranial to the lumbar intumescence.