Intervertebral Disc Extrusion Research Articles

The use of a minimally invasive integrated endoscopic system to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions.

The objective was to evaluate the use of a minimally invasive surgical (MIS) approach to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions (IVDE). Additionally, we aimed to evaluate the degree of soft tissue trauma using the endoscopic procedure compared to the standard open approach. Eight client-owned dogs presented to the Colorado State University Veterinary Teaching Hospital with acute onset thoracolumbar IVDE were included in this study. This was a prospective, randomized case-series. Patients were assigned to undergo an endoscopic (group 1; n = 4) or a standard open approach (group 2; n = 4) for a hemilaminectomy. A post-operative MRI was performed in all cases. Conversion to an open approach was not necessary for any case in group 1. All cases had adequate spinal cord decompression on post-operative MRI. There was no significant difference in soft tissue changes noted on post-operative MRI between the two groups. The MIS approach to hemilaminectomies in chondrodystrophic dogs with thoracolumbar IVDE can successfully be performed to decompress the neural tissue and appears to lead to similar clinical outcomes in the early postoperative period compared to the standard open approach. Larger studies are needed to determine the potential advantages of the MIS technique compared to the standard open approach in veterinary medicine.

Dorsal laminectomy for the treatment of lateralised cervical intervertebral disc extrusions in dogs-Prognosis and complications.

Describe the complication rate, expected hospitalization time and prognosis associated with dorsal laminectomy for the treatment of lateralised cervical intervertebral disc extrusion (IVDE) in dogs. This is a single-center retrospective case series study. Databases were reviewed from 2012 to 2022 for dogs that had a dorsal laminectomy to treat a lateralised cervical IVDE. Dogs were excluded if additional surgical techniques were performed, or other comorbidities were found on MRI. Fifty two dogs were included the study. French bulldogs represented 28.8% of the cohort. Patient median age was 6 years and median weight 15 kg. Thirty-five dogs (67.3%) presented clinical signs for <3 days and almost half (44.2%) were ambulatory but presented cervical pain and neurological deficits. Median surgical time was 85 min. Minor intraoperative complications were reported in 22 (42.3%), with hypothermia being the most common. Thirteen (25%) needed revision surgery due to persistent cervical pain with (9/13) or without (4/13) neurological deficits. Re-extrusion or persistent extrusion was found in 92.3% of cases needing surgical revision. Median hospitalization time was 6 days. Forty-seven (90.4%) cases had a good outcome. Despite the relatively high rate of intraoperative complications and cases needing revision surgery, dorsal laminectomy as surgical treatment for lateralised cervical IVDE is still associated with good long-term prognosis in most of cases. Prognosis is good even when revision surgery is necessary but expected hospitalization time seems to be higher when compared to an alternative surgical technique.

Investigation of neutering status and age of neutering in female Dachshunds with thoracolumbar intervertebral disc extrusion.

To evaluate neutering status and age of neutering in female Dachshunds with thoracolumbar intervertebral disc extrusion. We hypothesised that neutered Dachshunds presented with intervertebral disc extrusion at an earlier age, with a higher grade of neurological deficits and with more extensive extrusion of disc material compared with intact females. Retrospective multi-centre study of client-owned female Dachshunds with surgically confirmed thoracolumbar intervertebral disc extrusion. Dogs were classified as early, late or not neutered (intact). Age, body condition score, duration of clinical signs before presentation, modified Frankel score at presentation, length of extruded disc material, maximum spinal cord compression and whether dogs presented for a subsequent intervertebral disc extrusion were recorded. One hundred and fifty-four dogs were included: 36 early neutered, 69 late neutered and 49 intact. No significant difference was found between early neutered, late neutered and entire female Dachshunds in any of the variables studied. In this cohort of female dogs, neuter status and age of neutering were not found to affect age at onset nor severity of thoracolumbar intervertebral disc extrusion.

Investigating the weekend effect in decompressive thoracolumbar hemilaminectomy for acute intervertebral disc extrusion: An observational cohort study of 460 cases (2018-2023).

To investigate if weekend surgery is associated with poorer outcomes in dogs with acute thoracolumbar intervertebral disc extrusion (IVDE) undergoing decompressive thoracolumbar hemilaminectomy. Retrospective observational cohort study. A total of 460 consecutive cases were reviewed, with 401 dogs undergoing weekday surgery (Cohort WD), and 59 dogs undergoing weekend surgery (Cohort WE). Medical records of a surgical referral center in the UK were reviewed. Preoperative patient demographic and clinical data, and postoperative outcome data were collected with a minimum 28-day follow-up period. Multivariable logistic regression analysis was used to model the odds of a negative outcome. Cohort WE had a higher preoperative proportion of nonambulatory dogs (p = .0115) but there were no significant differences between the nonambulatory (p = .3762) and deep-pain negative subgroups (p = .6199). Cohort WE had a higher risk of not recovering ambulation compared to Cohort WD [79.2% vs. 91.6% recovery; adjusted OR 3.010 (95% CI: 1.259-7.190); p = .0132] and had a higher risk of postoperative morbidity [32.2% vs. 17.2%; adjusted OR 2.015 (95% CI: 1.089-3.729); p = .0257]. There were no significant differences in other outcome measures between cohorts. Weekend surgery in canine decompressive thoracolumbar hemilaminectomy may be associated with poorer patient outcomes, specifically higher postoperative morbidity and a poorer rate of recovery of ambulation. This study demonstrates a weekend effect in veterinary surgery, which may be important in surgical decision-making in acute thoracolumbar IVDE. Further scrutiny of the patient's journey through the veterinary healthcare system is warranted.

Outcome of the Use of Clinical Reasoning Alone in Dogs with Acute Thoracolumbar Myelopathy and/or Pain.

Acute thoracolumbar myelopathy is a common neurological presentation in dogs. Although certain spinal conditions present with characteristic clinical pictures, managing such cases with clinical reasoning alone (i.e., without cross-sectional imaging) has never been explored. The aim of this study was to define the outcome of patients with suspected intervertebral disc extrusion (IVDE), ischaemic myelopathy (IM) or acute non-compressive nucleus pulposus extrusion (ANNPE) that were managed with clinical reasoning alone. The database of the Queen's Veterinary School Hospital (Cambridge) was searched for paraparetic or paraplegic dogs with suspected IVDE or IM/ANNPE that were initially managed medically without undergoing imaging. Clinical presentation and outcome were recorded. If cross-sectional imaging was subsequently performed, information about the final diagnosis was collected and compared with the initially suspected diagnosis. A total of 123 IVDE cases were collected: 81% had a successful outcome with no imaging performed; 16% had IVDE confirmed with imaging and successful outcome with surgery or medical management; and just 3% were found to have an alternative diagnosis or were euthanised without imaging. A total of 16 IM/ANNPE cases were collected: 94% had a successful outcome, and one dog was euthanised. Successful outcomes can be obtained by using clinical reasoning alone in most dogs with suspected IVDE or IM/ANNPE.

Prevalence, clinical presentation, and etiology of myelopathies in 224 juvenile dogs.

Intervertebral disc herniation is widely recognized as the most common cause of myelopathy in dogs older than 2 years; however, the prevalence of various causes of myelopathy in younger dogs has not been reported. To describe the prevalence, clinical presentation, and etiology of myelopathy in dogs aged 18 months or less. Secondarily, to investigate which clinical features were associated with each of the most common etiologies. Two hundred twenty-four dogs aged 18 months or less with myelopathy were included in the study. Retrospective review of clinical records from 4 referral institutions. Multivariable logistic regression analyses assessed which clinical features were associated with each diagnosis. French bulldogs (n = 51, 22.8%), pugs (n = 18, 8.0%), crossbreeds (n = 12, 5.4%), and English bulldogs (n = 11, 4.9%) were the most frequently affected breeds. Overall, 31 diagnoses were reached. The 5 most frequent diagnoses were vertebral malformation (VM; n = 42, 18.8%), spinal arachnoid diverticulum (SAD; n = 28, 12.5%), traumatic fracture of the vertebral column (n = 22, 9.8%), atlantoaxial instability (n = 18, 8.0%), and osseous-associated cervical spondylomyelopathy (n = 17, 7.6%). Intervertebral disc extrusion (IVDE) accounted for 4.5% of cases (n = 10). A final diagnosis of VM was associated with younger, screw-tailed, and pug breeds with chronic signs of T3-L3 myelopathy. SAD was associated with screw-tailed and pug breeds with nonpainful clinical signs. Intervertebral disc extrusion was associated with older, screw-tailed, and pug breeds with shorter duration of clinical signs. Prioritization of differential diagnoses for dogs presenting with signs of myelopathy when aged 18 months or less should differ to those for older dogs, with IVDE not the most common cause in the former.

Extrusão de disco intervertebral em Buldogue Francês

Também conhecida como hérnia de disco ou discopatia canina, a extrusão de disco intervertebral em cães é uma doença degenerativa crônica ou aguda, muito comumente encontrada em clínica médica de pequenos animais, em que ocorre o “extravasamento” do disco intervertebral. Essa discopatia está dividida em três tipos, conhecidas como doença de Hansen tipo I, II e III. Este trabalho tem como objetivo descrever um relato de caso de extrusão de disco intervertebral ocorrido em Bulldog Francês desde a sua chegada na clínica até a recuperação do paciente e suas características como sintomatologia, diagnóstico e tratamento. O caso foi acompanhado durante o estágio curricular obrigatório em Medicina Veterinária na clínica Focinhos e Patinhas, em Curitiba no estado do Paraná.

Spontaneous resorption of a C7–T1 intervertebral disc extrusion in a Cavalier King Charles spaniel confirmed via low‐field MRI

AbstractA 4‐year‐old, male, neutered Cavalier King Charles spaniel was referred to the neurology service with a 10‐day history of cervical hyperaesthesia. A low‐field magnetic resonance imaging scan of the cervical spine identified a large C7–T1 intervertebral disc extrusion, resulting in severe spinal cord compression. The patient was treated with conservative therapy (exercise restriction and analgesia for 4 weeks). Repeat magnetic resonance imaging of the cervical spine was performed 4 months after initial presentation, and identified spontaneous resorption of the extruded C7–T1 disc material. There are very few documented cases of spontaneously resorbed cervical intervertebral disc extrusions in canine patients following successful conservative therapy. To the authors’ knowledge, this is the first report of spontaneous resorption of an intervertebral disc extrusion at an unusual C7–T1 location confirmed via follow‐up low‐field magnetic resonance imaging following conservative therapy.

Residual volume of extruded disc material and residual spinal cord compression measured on postoperative MRI do not predict neurological outcomes in dogs following decompressive surgery for thoracolumbar intervertebral disc extrusion.

Published studies on the validity of using quantitative MRI measures of pre- and postoperative spinal cord (SC) compression as prognostic indicators for dogs undergoing surgery for intervertebral disc extrusion (IVDE) are currently limited. The aim of this retrospective analytical study was to describe the volume of postoperative residual extradural material (VREM) and the ratio of the cross-sectional area (CSA) of maximum SC compression to the CSA of SC in a compression-free intervertebral space as MRI measures of preoperative and postoperative compression (residual spinal cord compression, RSCC), and to compare these measures between the neurological outcome in a group of dogs. Inclusion criteria were dogs that underwent surgery for thoracolumbar IVDE, were imaged pre- and immediately postoperatively by MRI, and had a neurological follow-up examination 2 to 5 weeks postoperatively. Two blinded observers independently performed measurements in pre- and postoperative MRI studies. Dogs were classified into positive outcome (PO) and negative outcome (NO) groups based on follow-up neurologic examination scores. Seventeen dogs were included (12 PO, 5 NO). Interobserver agreement for MRI measurements was good to excellent (ICCs: 0.76-0.97). The prevalence of residual extradural material in postoperative MRI studies was 100%. No significant differences in mean preoperative SC compression, mean RSCC, mean SC decompression, or VREM were found between outcome groups (P=.25; P=.28; P=.91, P=.98). In conclusion, neither postoperative VREM nor RSCC could predict successful neurological outcomes.

Estimativa de perda sanguínea transoperatória em cães submetidos a hemilaminectomia e fenestração do disco intervertebral

ABSTRACT: There are no reported estimates of normal or abnormal bleeding in dogs during the hemilaminectomy and intervertebral disc fenestration procedures (HF), and that makes it difficult to study intraoperative complications, hemostasis methods, and the impact of bleeding on surgical performance. This prospective study estimated blood loss during HF procedures in dogs with intervertebral disc extrusion (IVDE). Blood loss was quantified by weighing gauzes during the surgical procedure, in addition to measuring the aspirated blood. Total blood volume was estimated according to body weight, and blood loss as a percentage of the total blood volume. The surgeon also subjectively classified the procedures, dividing them into intraoperative difficulty due to bleeding (G1) and absence of intraoperative difficulty (G2). Thirty-two dogs that underwent HF due to IVDE were included. The median blood loss (%) of dogs submitted to HF was 3.9 ± 9.67 of the total blood volume. There was a weak correlation between blood loss and weight, age, incision size, and procedure time.

Сравнительный анализ влияния декомпрессионных методик на диапазон движения позвонков в грудопоясничном отделе позвоночного столба у собак

The work was carried out with the aim of conducting a comparative analysis of the effect of hemilaminectomy and mini-hemilaminectomy on the range of motion of the vertebrae in the thoracolumbar spine in dogs and to establish a correlation between changes in the range of motion of the vertebrae at the site of decompression and in adjacent spinal motion segments with the incidence of relapses of intervertebral disc extrusions and the emergence of a «domino effect». The research was carried out in 2023 on the basis of the Department of Veterinary Surgery of the Federal State Budgetary Educational Institution of Higher Education MGAVMiB – MBA named after K. I. Scriabin. The object of the study was sectioned material from dogs of chondrodystrophic breeds (n=5), the subject of the study was the thoracolumbar section of the spinal column Th10-S1. The range of motion of the vertebrae in each individual spinal motion segment was studied by comparing their positions in the neutral position, during flexion and during extension: in the native state – 3 samples, in the native state and after hemilaminectomy at the Th13-L1 level – 1 sample, in in the native state and after performing a mini-hemilaminectomy at the Th13-L1 level – 1 sample. At the site where the decompression technique was applied, the range of Th13-L1 vertebral motion increased by 51,66 % with hemilaminectomy and decreased by 0,76 % with mini-hemilaminectomy (the difference is statistically significant, p=0.001). In the adjacent spinal motion segment Th12– Th13, the range of vertebral motion increased by 22,25 % with hemilaminectomy and by 8,39 % with mini-hemilaminectomy (the difference is statistically significant, p=0,01). The correlation coefficient between the frequency of relapses of extrusions and changes in the range of motion of the vertebrae at the site of decompression is 0,71, which indicates a relationship between the average tightness between the analyzed indicators. The correlation coefficient for the risk of the «domino effect » and changes in the range of motion of the vertebrae in spinal motion segments adjacent to the site of decompression is 0,77, which indicates a strong correlation between the analyzed indicators.

Conservative treatment of recurrent intervertebral disc extrusions in a lionhead rabbit

ABSTRACTA 4‐year‐old lionhead rabbit with an acute onset of abnormal hindlimb gait was presented. L4–S3 neurolocalisation was determined based on clinical findings of paraparesis, bilateral proprioceptive positioning deficits, left pelvic limb hyporeflexia and discomfort during lumbar spine manipulation. The magnetic resonance imaging (MRI) revealed an intervertebral disc extrusion (IVDE) at L4–L5, with mild spinal cord compression. The condition was treated conservatively, with cage rest and non‐steroidal anti‐inflammatory drugs. The rabbit was fully normal after 1 month. Two months later, a relapse of clinical signs was observed. A new MRI study revealed a L5–L6 IVDE with mild spinal cord compression. Conservative treatment was repeated and full recovery was confirmed at 4‐month follow‐ups associated with MRI follow‐up study. To the authors' knowledge, this is the first case report of spontaneous IVDEs in a rabbit, where MRI was used to monitor the effectiveness of the conservative management of the disease in a rabbit.

Paracetamol add-on treatment for perioperative pain management in dogs undergoing single-site thoracolumbar hemilaminectomy: a prospective clinical study

In this prospective, double-blinded, randomized, clinical trial, it was evaluated whether paracetamol, as an adjunct to NSAID and opioid analgesia, might limit the requirements for intraoperative fentanyl and postoperative methadone administration in dogs undergoing a singlesite thoracolumbar hemilaminectomy for surgical treatment of an intervertebral disc extrusion. Twelve client-owned dogs were randomly assigned to two multimodal analgesia groups: NSAID + paracetamol group (group NP) and NSAID + placebo group (group N). Intraoperative analgesic assessment was based on the clinical evaluation of a nociceptive response, whereas postoperative analgesic assessment was determined by using the short form of the Glasgow Composite Pain Scale. No statistically significant difference was found in both groups for the intraoperative need for fentanyl (P = 0.18). The probability of having to administer rescue analgesia postoperatively was significantly higher in group N than in group NP (P = 0.01). For both groups, there were no serious side effects reported, nor was any significant difference found between both groups regarding the occurrence of side effects (P = 0.55). Despite multimodal perioperative pain management consisting of a full μ-agonist opioid, a NSAID and paracetamol, intraoperative rescue analgesia was still required, although the need for postoperative opioid based analgesia was significantly lower in group NP.

Perioperative analgesic efficacy of lumbar erector spinae plane block in dogs undergoing hemilaminectomy: a randomized blinded clinical trial

ObjectiveTo evaluate the perioperative analgesic effect of the unilateral lumbar erector spinae plane block (ESPBL) in dogs undergoing hemilaminectomy. Study designRandomized, blinded clinical study. AnimalsA total of 30 client-owned dogs undergoing thoracolumbar or lumbar hemilaminectomy for intervertebral disc extrusion (IVDE). MethodsDogs were randomly assigned to receive a unilateral ESPBL, performed either with 0.4 mL kg−1 ropivacaine 0.5% [group ROPI (n = 15)] or with saline solution [CNT group (n = 15)]. Dogs were premedicated intravenously (IV) with acepromazine 5 μg kg−1 and methadone 0.2 mg kg−1, general anaesthesia was induced by administering IV midazolam 0.2 mg kg−1 and propofol to effect and maintained with isoflurane. Fentanyl was administered as rescue analgesia. Bradycardia [heart rate (HR) < 60 beats minute−1] with hypotension was treated with atropine IV. The Short-Form of the Glasgow Composite Pain Scale was used pre- and postoperatively at 1, 2, 4, 8, 12, 16, 20 and 24 hours after extubation, and methadone 0.2 mg kg−1 was administered IV when pain score was ≥ 5/20. HR and end-tidal concentration of isoflurane (Fe'Iso) were compared between groups with anova combined with a Dunnet’s post hoc test. Time to the first rescue methadone and total dose of fentanyl (FENtot, μg kg−1 hour−1) and methadone (METtot, mg kg−1) in the first 24 postoperative hours were compared using unpaired Student’s t test. Postoperative pain scores were compared with the Mann–Whitney test and atropine administration with a Fisher’s exact test; p < 0.05. ResultsHR, Fe'Iso, FENtot, METtot and atropine administration were significantly lower in group ROPI compared to CNT. Postoperative analgesic effect was significantly longer, and pain scores were significantly lower in group ROPI for all time points. Conclusions and clinical relevanceUnilateral ESPBL with ropivacaine reduced perioperative opioid consumption and the occurrence of bradycardia in dogs undergoing hemilaminectomy.

Possible case of prefixed brachial plexus in a dog with a caudal cervical intervertebral disc extrusion

AbstractA 5‐year‐old, entire, male dachshund was referred with a 7‐day history of non‐ambulatory paraparesis. The neurological examination was most consistent with a T3–L3 myelopathy. Magnetic resonance imaging and computed tomography studies of the cervical, cervicothoracic and thoracolumbar regions revealed a C7–T1 intervertebral disc extrusion causing moderate spinal cord compression. Based on the clinical presentation and imaging findings, a presumptive diagnosis of intervertebral disc extrusion in a dog affected by suspected prefixed brachial plexus was made. The dog underwent a ventral slot decompressive surgery, and its neurological conditions improved shortly after. The discrepancy between neuroanatomical localisation and location of an intervertebral disc extrusion may represent a possible instance of prefixed brachial plexus. To the authors’ best knowledge, prefixed brachial plexus has not been reported in dogs to date.

Prevalence, MRI findings, and clinical features of lumbosacral intervertebral disc protrusion in French Bulldogs diagnosed with acute thoracic or lumbar intervertebral disc extrusion

Prevalence, MRI findings, and clinical features of lumbosacral intervertebral disc protrusion in French Bulldogs diagnosed with acute thoracic or lumbar intervertebral disc extrusion

Respiratory compromise in French bulldogs presented with intervertebral disc extrusion.

French bulldogs hospitalised for the management of intervertebral disc extrusion (IVDE) are frequently affected by respiratory compromise, typically brachycephalic-associated upper respiratory obstruction and/or aspiration events. We evaluated the occurrence of such respiratory compromise events in French bulldogs presented to two referral hospitals. Clinical data for French bulldogs diagnosed with IVDE were retrospectively collated, including severity of neurological deficits, neuroanatomical localisation, diagnosis, details of respiratory compromise, treatment and outcome. A total of 306 dogs diagnosed with IVDE were included. Sixty dogs (19.6%) experienced respiratory compromise, of which 31 dogs (10.1%) progressed to cyanosis, collapse or respiratory arrest. The study was limited by its retrospective nature. Furthermore, the duration of hospitalisation was not evaluated and the decision for euthanasia was often multifactorial. One in five French bulldogs presented with IVDE experienced respiratory compromise. The detrimental welfare effects of this warrant further discussion.

Accuracy of low-field magnetic resonance imaging for differentiating intervertebral disc extrusions and protrusions at the lumbosacral disc space in dogs.

MRI features differentiating extrusion from protrusion in thoracolumbar discs have been published, however little specifically evaluates the lumbosacral disc. The high prevalence of degenerative changes in apparently normal animals complicates assessment of this region and features relevant elsewhere in the spine may not apply. The aims of this study were to determine the accuracy of MRI in differentiating IVDE and IVDP at the lumbosacral disc space in dogs and determine which MRI characteristics discriminate between IVDE and IVDP. MRI examinations from dogs with surgically confirmed IVDE or IVDP at the lumbosacral disc space were collected retrospectively (2011-2019). Two radiologists independently recorded a diagnosis of IVDE or IVDP, gave a confidence rating, and evaluated specific MRI features. Univariable statistical analysis was performed to identify which MRI characteristics might help distinguish IVDE from IVDP. 117 dogs with lumbosacral IVDE (n = 16) or IVDP (n = 101) were included. Features associated with IVDE were in concordance with previous studies and included interruption of the dorsal annulus, suspected epidural hemorrhage, dispersed (rather than confined) intervertebral disc herniation on T2W sagittal images, lateralized intervertebral disc herniation and displacement of the cauda equina. Overall diagnostic accuracy was 68.8% and interobserver agreement was fair (κ = 0.37), which is lower than has been reported in thoracolumbar disc herniation, but accuracy increased to 85.3% with substantially improved agreement (κ = 0.87) in "confident" diagnoses. MRI characteristics used in differentiating thoracolumbar IVDE and IVDP can be extrapolated to the lumbosacral intervertebral disc space, but diagnostic accuracy in low-field MRI is lower than previously reported in herniations involving the thoracolumbar spine.

Tranexamic Acid in Reducing Intraoperative Bleeding in Dogs Undergoing Thoracolumbar and Lumbar Hemilaminectomy and Intervertebral Disc Fenestration

Hemilaminectomy associated with intervertebral disc fenestration (HF) is the most used spinal decompression surgical technique for the treatment of intervertebral disc extrusion (IVDE). The surgical procedure can be hampered by excessive bleeding from the venous sinuses; however, tranexamic acid intravenously (IV) is a possible adjunct to hemostasis in these patients. This study aimed to verify the effectiveness of tranexamic acid in reducing intraoperative bleeding in dogs with thoracolumbar and lumbar IVDE submitted to HF. Sixteen dogs with IVDE undergoing HF were included. These were distributed into a TXA group (tranexamic acid 20 mg/kg IV bolus, followed by 2 mg/kg/h IV continuous infusion) (n = 8) and a control group, with saline solution (n = 8). Blood loss was measured using the gravimetric method. The difficulty of operative visualization due to bleeding was classified by the surgeon. Median blood loss (%) in patients in the TXA group was lower than those in the control group (2.75 ± 1.23 and 4.99 ± 4.44, respectively) (P = .028). Intraoperative visualization difficulty due to bleeding occurred in 10 patients in the control group, and in no patients in the TXA group. A severe arterial thromboembolic complication was recorded, potentially due to tranexamic acid. The use of intraoperative tranexamic acid was effective in reducing bleeding and facilitating operative visualization in dogs with IVDE undergoing hemilaminectomy and intervertebral disc fenestration.

Adaptation of land treadmill scoring system for underwater treadmill in dogs with thoracolumbar intervertebral disc extrusion

The underwater treadmill (UWTM) is utilized in dogs recovering from thoracolumbar intervertebral disc extrusion (TL-IVDE). Gait scoring is validated for dogs with TL-IVDE walking on the land treadmill (LT) but has not been reported for the UWTM. Our objective was to investigate if LT gait analysis could be applied to the UWTM and if non-ambulatory dogs walking unassisted on the UWTM, at a standardized water level, would be more likely to generate gait scores compared to on the LT. This was a prospective, observational study in dogs with TL-IVDE managed surigcally. At 0, 2, 4, 8 and 12 weeks post-operatively, paired video footage of dogs walking on the LT and UWTM (water level at the greater trochanter) was used to generate 0–100 stepping (SS) and coordination (regularity index, RI) scores. Scores were compared between treadmill type and over time. Twenty dogs were enrolled and seventy-eight paired recordings were available for review. Median gait scores increased over time but did not differ by treadmill type (P = 0.262 for SS, P = 0.533 for RI). Combining SS and RI, more recordings received scores of 0 for the LT (n = 58/156; 37.2 %) compared to the UWTM (n = 44/156; 28.2 %; P = 0.043). Scores of 0, at visits when there was at least movement present at multiple joints, was more common on the LT (n = 11/108; 10.2 %) compared to the UWTM (n = 2/108, 1.9 %; P = 0.026). In dogs recovering from TL-IVDE, LT-based gait scoring was feasible in dogs walking on the UWTM and might complement other gait analysis methods, especially for non-ambulatory dogs.