Computed tomographic and histological findings of Hansen type I intervertebral disc herniation in dogs

Interobserver agreement of computed tomography in detecting calcified intervertebral discs in comparison with radiography in a population of 13 healthy British Dachshund dogs

Background

The aims of this retrospective study were to estimate interobserver agreement in detecting disc calcification with computed tomography (CT) and to compare the number of calcified intervertebral discs identified on CT and radiography in healthy British Dachshund dogs that underwent a screening programme. The current screening programme uses radiography to identify calcified intervertebral discs.

Methods

Healthy Dachshunds aged between 2 and 5 years presenting for spinal radiography and CT as part of a disc scoring scheme were included. The spinal radiographs were scored by an independent assessor as per the screening programme protocol. The CT images were blinded and reviewed by three different observers of differing levels of experience. The number of discs identified as being calcified was then compared between imaging modalities and between observers.

Results

Thirteen dogs were included. Overall, 146 calcified discs were identified by CT compared with 42 by radiography. There was an almost perfect agreement among the three observers identifying calcified discs with CT images (k = 0.92). There was a significant difference between the radiography scores and CT scores.

Conclusions

This study demonstrated a significant difference in the number of calcified intervertebral discs identified in the vertebral column of a small population of healthy Dachshunds between CT and radiography. Given the high agreement between the observers with CT, this may be a reliable method for assessing disc calcification in Dachshund dogs and could be a good candidate for future breeding schemes.

ACVIM consensus statement on diagnosis and management of acute canine thoracolumbar intervertebral disc extrusion

Background

Thoracolumbar intervertebral disc extrusion (TL‐IVDE) is the most common cause of acute paraparesis and paraplegia in dogs; however, guidelines on management of the condition are lacking.

Objectives

To summarize the current literature as it relates to diagnosis and management of acute TL‐IVDE in dogs, and to formulate clinically relevant evidence‐based recommendations.

Animals

None.

Methods

A panel of 8 experts was convened to assess and summarize evidence from the peer‐reviewed literature in order to develop consensus clinical recommendations. Level of evidence available to support each recommendation was assessed and reported.

Results

The majority of available literature described observational studies. Most recommendations made by the panel were supported by a low or moderate level of evidence, and several areas of high need for further study were identified. These include better understanding of the ideal timing for surgical decompression, expected surgical vs medical outcomes for more mildly affected dogs, impact of durotomy on locomotor outcome and development of progressive myelomalacia, and refining of postoperative care, and genetic and preventative care studies.

Conclusions and Clinical Importance

Future efforts should build on current recommendations by conducting prospective studies and randomized controlled trials, where possible, to address identified gaps in knowledge and to develop cost effectiveness and number needed to treat studies supporting various aspects of diagnosis and treatment of TL‐IVDE.

Investigation of parameters predicting the need for diagnostic imaging beyond computed tomography in the evaluation of dogs with thoracolumbar myelopathy: Retrospective evaluation of 555 dogs

Thoracolumbar myelopathy encompasses a number of disease processes such as intervertebral disc disease, discospondylitis, trauma, congenital malformations, neoplasia, and intramedullary spinal cord disease. Compressive disc herniations are most common in dogs and require imaging procedures such as myelography, computed tomography (CT), and/or magnetic resonance imaging (MRI) to determine the need and location for decompressive surgery. The purposes of this retrospective, cross-sectional study were to evaluate all dogs undergoing thoracolumbar CT imaging as the initial diagnostic step between 2010 and 2015 and determine whether any of the imaging characteristics could be used to predict the need for additional imaging in the form of myelography, CT myelography, and/or MRI. A total of 555 dogs were identified in this time frame which underwent CT imaging for myelopathy of the thoracolumbar region. Various parameters including age, gender, sexual status, breed, chronicity, site of lesion, time of study, and contrast administration were evaluated. Findings indicated that 7.6% of dogs needed additional imaging after CT. Dachshunds were less likely to need additional imaging (P = 0.0111) as were patients scanned during normal business hours (P = 0.0075). Increasing age of the patient increased the likelihood of additional imaging (P = 0.0107). Dogs which did not have additional imaging performed were 21.89 times more likely to require surgery than those which did have additional imaging (P < 0.0001). Findings supported the use of CT as a first-line imaging modality for dogs presenting with thoracolumbar myelopathy.