Presumptive exercise-associated peracute thoracolumbar disc extrusion in 48 dogs.

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.

Hemilaminectomy and vertebral stabilisation for the treatment of thoracolumbar disc protrusion in 28 dogs.

OBJECTIVES: To evaluate the results of hemilaminectomy and vertebral stabilisation (+/- annulectomy) for the treatment of thoracolumbar disc protrusion. METHODS: The medical records of dogs with thoracolumbar annular protrusions treated by hemilaminectomy and vertebral stabilisation were reviewed. Neurological function was assessed 24 hours following surgery. Long-term follow-up was by clinical examination or telephone questionnaire. RESULTS: Twenty-eight dogs fulfilled the criteria. Age ranged from 4 to 12.5 years (median 8 years, mean 7.7 years), bodyweight from 5.1 to 51.5 kg (median 28 kg, mean 27.1 kg), and duration of neurological signs before presentation from 48 hours to 104 weeks (median 5 weeks, mean 9.3 weeks). At presentation 22 dogs were ambulatory and six were non-ambulatory. Myelography and/or magnetic resonance imaging (MRI) identified 31 thoracolumbar protrusions causing spinal cord compression. Unilateral hemilaminectomy was performed in 27 dogs and bilateral hemilaminectomy in one dog. Partial annulectomy was performed in 24 of 31 protrusions. Stabilisation was performed using vertebral body bone plates in 26 dogs and vertebral body screws and bone cement in two dogs. Internal vertebral venous plexus haemorrhage was recorded in nine dogs. A screw was inadvertently placed into an intervertebral disc in two dogs. Neurological examination 24 hours postoperatively revealed deterioration in pelvic limb motor function in 17 dogs. One dog was euthanatised at the owner's request 6 days after surgery. Long-term evaluation of 24 cases was performed 3 to 52 months following surgery (median 21 months, mean 23.9 months). Six dogs had improved from their preoperative status and one had deteriorated as assessed by the authors. Fifteen dogs had improved from their preoperative status and two were unchanged as assessed by owners. CLINICAL SIGNIFICANCE: Hemilaminectomy and vertebral stabilisation are an effective treatment for chronic spinal cord compression due to thoracolumbar annular protrusion in dogs. A temporary deterioration in neurological function is not uncommon following surgery. Internal vertebral plexus haemorrhage and inappropriate vertebral body screw placement are potential complications.

Vertebral stabilisation and selective decompression for the management of triple thoracolumbar disc protrusions.

Triple adjacent thoracolumbar disc protrusions causing moderate to severe spinal cord compression were diagnosed by magnetic resonance imaging in two German shepherd dogs with marked paraparesis and pelvic limb ataxia. Both cases were managed by selective hemilaminectomy, partial annulectomy and bilateral quadruple vertebral body stabilisation using novel canine locking fixation plates (SOP). The stabilisation of multiple vertebrae in the thoracolumbar spine was possible because the plates could be contoured with six degrees of freedom. Spinal pain resolved and neurological function improved in both dogs. Screw breakage was evident in one dog five months following surgery.

Rupture of the dura mater in two dogs caused by the peracute extrusion of a cervical disc.

A rupture of the dura mater caused by the peracute extrusion of a cervical disc was diagnosed by myelography in two dogs. In both cases traction on the cervical spine resulted in contrast medium entering the ruptured intervertebral disc from the subarachnoid space. Both dogs became suddenly tetraparetic and unable to ambulate during vigorous exercise, but regained the ability to walk without surgical treatment.

Partial molar heat capacities of the peptides glycylglycylglycine, glycyl-L-alanylglycine and glycyl-DL-threonylglycine in aqueous solution over the temperature range 50 to 125 degrees C.

Partial molar heat capacities of the three tripeptides glycylglycylglycine, glycyl-L-alanylglycine and glycyl-DL-threonylglycine in aqueous solution at the temperatures 50, 75, 100 and 125 degrees C have been determined using differential flow calorimetry. The results have been used to estimate the contributions to the partial molar heat capacities of peptides of the alanyl and threonyl side-chains. These side-chain contributions are compared with those reported in the literature.