Clinical presentation, magnetic resonance imaging findings, and outcome of 80 Dachshunds with cervical intervertebral disc extrusion.

Introduction: Large clinical studies regarding cervical intervertebral disc extrusion (IVDE) in Dachshunds are lacking. This retrospective multicentric study therefore aims to describe the clinical features, magnetic resonance imaging (MRI) findings and outcomes of Dachshunds diagnosed with cervical IVDE. Methods: Medical records of Dachshunds with cervical IVDE were reviewed for signalment, onset of clinical signs, neurological examination, MRI features, treatment and outcome. Results: Eighty Dachshunds were included in the study, mostly ambulatory (55% grade 1 and 33% grade 2) and without nerve root signature (85% of cases) on presentation. Information on coat type was available for 56% of dogs; specifically, 41% were smooth-haired, 9% were long-haired and 6% were wire-haired Dachshunds. There were 29 (36%) neutered female, 27 (34%) male entire, 15 (19%) male neutered and 9 (11%) entire female dogs. The onset of clinical signs was most often >48 h (84%). The most common intervertebral disc space affected was C2-C3 (38%) and foraminal IVDEs were reported in 14% of dogs. A foraminal IVDE was diagnosed in only 25% of dogs presented with nerve root signatures. Most dogs (77.5%) were treated surgically. In this group, a higher body condition score on presentation and a higher mean spinal cord compression ratio calculated on MRI were directly and moderately associated with a longer hospitalization time (r = 0.490 p = 0.005 and r = 0.310 p = 0.012, respectively). The recovery time was longer in dogs with an onset of clinical signs <24 h or 24-48 h compared to those with an onset of clinical signs >48 h (3.1 ± 6.5 days versus 1.6 ± 6.2, p < 0.001) in both medically and surgically treated groups. Data about the outcome was available for 83% of dogs. Eighty percent of the entire population of dogs was considered to have completely returned to normal. There was no association between the therapeutic choice (surgical versus medical management) and the outcome of the dogs included in this study.

Clinical outcomes of 20 brachycephalic dogs with thoracolumbar spinal deformities causing neurological signs treated with spinal stabilization using 3D-printed patient-specific drill guides.

OBJECTIVE: To describe the clinical outcomes for pugs and French bulldogs with congenital vertebral malformations, undergoing thoracolumbar spinal stabilization surgery using 3D-printed patient-specific drill guides. To evaluate the accuracy of pedicle screw placement in this group of dogs. STUDY DESIGN: Retrospective descriptive study. ANIMALS: Twenty dogs (12 pugs and eight French bulldogs). METHODS: Medical records searched between August 2018 and March 2021 for pugs and French bulldogs diagnosed with congenital vertebral abnormalities via magnetic resonance imaging (MRI) scan and computed tomography (CT) scan causing T3-L3 myelopathy signs that underwent spinal stabilization surgery using 3D-printed patient-specific drill guides followed by a postoperative CT scan. The short-term outcome was based on the neurological grade (modified Frankel score-MFS) on the day after surgery, day of discharge, and at the follow-up examination at 4 to 6 weeks after surgery. The mid-term outcome was obtained via an online questionnaire (or direct examination in one case). RESULTS: Twenty dogs met the inclusion criteria (19/20 grade 2 MFS, 1/20 grade 4 MFS). No complications were reported in the immediate postoperative period and optimal pedicle screw placement was obtained in 169/201 of screws. Twenty-four hours after surgery 16/20 dogs displayed an unchanged neurological grade. Short-term outcomes revealed a static (17/20) or improved (2/20) neurological grade. Ten owners participated in the online questionnaire. All patients were reported to be ambulatory; however, 7/10 dogs displayed abnormal gait. Neurological signs had remained static (6/10) or improved (3/10) in comparison with the dogs' preoperative status at a median of 883.5 days from the surgery. CONCLUSION: Dogs in this study had a favorable short-term outcome and mid-term outcome evaluation revealed a static/improved neurological status. CLINICAL SIGNIFICANCE: Thoracolumbar spinal stabilization surgery using 3D-printed patient-specific drill guides showed a favorable outcome in brachycephalic breeds affected by vertebral deformities.

Magnetic resonance imaging features of canine intradural/extramedullary intervertebral disc extrusion in seven cases.

Intervertebral disc disease, including intervertebral disc extrusions and protrusions, is the most common spinal cord disorder in dogs. Atypical and uncommon intervertebral disc herniations include intradural/intramedullary disc extrusion, intervertebral foraminal disc extrusion and intervertebral disc herniation (Schmorl's node). Intradural/extramedullary disc extrusion is the least common type of intervertebral disc herniation in veterinary medicine, characterized by extruded disc material within the intradural space. To date, only one study has been published in veterinary medicine reporting intradural/extramedullary disc extrusions. In this study, low field MRI was used, and the authors could not find any MRI features to diagnose with confidence an intradural/extramedullary disc location of the extruded disc material. The aim of this study was to describe the high field (1.5T) MRI characteristics of surgically confirmed intradural/extramedullary disc extrusions. This is a retrospective, multicentric and descriptive study. Inclusion criteria was surgical confirmation of intradural/extramedullary disc extrusion by durotomy and complete MRI study of the spine. Seven cases were included. Images were reviewed by a radiology resident and a certified radiologist, with emphasis on the following signs: "Golf-tee sign" (widening of the subarachnoid space cranial and caudal to the lesion), "Beak sign" (pointed and sharp compressive lesion) and "Y sign" (division of the dura and arachnoid layers). MRI showed a "Y sign" in all the cases (7/7) seen from the T2-weighted sagittal views, while "Golf-tee sign" was not recognized in any of the cases (0/7). Additionally, "beak sign" was present in half of the cases (4/7). "Y sign" maybe a reliable MRI feature for identifying intradural/medullary disc extrusions from the MRI study. As the arachnoid is peeled from the dura by the disc herniation there is a splitting of the arachnoid mater and the ventral dura. The intradural disc material will be surrounded by CSF signal intensity margin, giving the appearance of a Y, which can be identified from the T2-weighted sagittal images.