Forty-eight dogs were diagnosed with presumptive exercise-associated peracute thoracolumbar disc extrusion. The median age was seven years (range two to 11 years), and median bodyweight was 23 kg (range 10 to 41 kg). The duration of signs before presentation ranged from 0.5 to four days. Twenty-nine dogs were non-ambulatory, of which 17 were incontinent and two had lost pain perception. Pelvic limbs were hyporeflexic or areflexic in 11 dogs. Intervertebral disc narrowing was evident on radiographs in 44 dogs. Myelography demonstrated a small, extradural space-occupying lesion dorsal to an intervertebral disc between T11-12 and L3-4 with adjacent spinal cord swelling. Forty-six dogs were treated non-surgically, one was euthanased and one was managed by hemilaminectomy (and subsequently euthanased). Follow-up information was available for 46 dogs 1.5 to 55 months after injury (median 22 months) showing that pelvic limb function had improved in all cases and all non-ambulatory dogs had regained the ability to walk. Six dogs remained faecally incontinent, and one dog remained urinarily and faecally incontinent.