Abstract
Objectives
This study describes the imaging features of feline discospondylitis on MRI, comparing them with CT and radiographic findings where available.
Methods
The medical records of cats diagnosed with discospondylitis, presented to three referring institutions, were reviewed. MRI, CT and radiographic features were assessed by two of the authors independently.
Results
Fourteen sites of discospondylitis were retrospectively identified in 13 cats. The L7–S1 intervertebral disc space (IVDS) was affected in 7/14 (50%) cases. Characteristic MRI features included a hyperintense nucleus pulposus signal on T2-weighted (T2W) imaging (n = 10/14 [71%]) and short tau inversion recovery (STIR) imaging (n = 11/13 [85%]), with contrast enhancement in all (n = 11/11); involvement of adjacent vertebral endplates (n = 11/14 [79%]) and hyperintense neighbouring soft tissue on T2W (n = 11/14 [79%]) and STIR (n = 10/13 [77%]), with contrast enhancement in all (n = 11/11); and the presence of spondylosis deformans (n = 10/14 [71%]). Other features included narrowed or collapsed IVDS (n = 8/14 [57%]), contrast enhancement of vertebral bodies (n = 5/11 [46%]), epidural space involvement (n = 5/14 [36%]), compression of the spinal cord or nerve roots (n = 5/14 [36%]), paraspinal abscessation (n = 3/14 [21%]) and meningeal signal intensity abnormalities with contrast enhancement (n = 5/6 [83%]). These latter findings may indicate secondary focal meningitis. Radiographs were available covering five sites (in four cats) and CT covering three sites (in two cats). The most common radiological features were collapse or narrowing of the affected IVDS (80%) and endplate erosion (60%). No changes suggestive of discospondylitis were identifiable on radiography or CT in two sites (one cat), despite being identifiable on MRI. Repeated radiography in one case did not reveal complete radiological resolution following 9 months of treatment.
Conclusions and relevance
The results of this study indicate consistent MRI features of feline discospondylitis that should be considered in the diagnosis of this condition.
Introduction
Discospondylitis describes the infection of an intervertebral disc (discitis) and its adjacent cartilaginous vertebral endplates (spondylitis).1–5 This condition is well recognised and reported in dogs, with descriptions of its associated clinical signs, typical signalment and imaging characteristics.3,4,6 However, literature describing discospondylitis in cats is sparse, with six individual case reports and two cats being mentioned in a series of feline patients with spinal cord disease.7–13 Discospondylitis appears to be a rare condition in cats, more commonly identified in male cats, mainly at the level of the lumbar spine.7–12 Prognosis appears guarded, as 4/6 reported cases died (one case) or were euthanased (three cases) following diagnosis. Reported imaging investigations included vertebral radiographs in every case with additional CT or MRI in single cases.7,12
Discospondylitis in dogs can be challenging to diagnose as signs are variable and sometimes vague. Commonly described clinical signs include spinal hyperaesthesia, lethargy, reluctance to move, pyrexia, anorexia and weight loss.1,2,5 Neurological dysfunction can develop, usually secondary to abnormal osseous proliferation, empyema, focal meningitis/myelitis, subluxation or pathological fractures.4,5
Considering the variable and challenging clinical presentation, imaging is critical in establishing a diagnosis of discospondylitis. 5 A diagnosis of discospondylitis relies on a combination of compatible clinical signs, exclusion of other painful and debilitating conditions, culture and sensitivity results, and cytology on any available biopsy material. However, the clinical conundrum is that to attain a final diagnosis based on histopathology and culture, imaging features need to be identified, in order to recognise the need for further procedures. Moreover, blood or urine culture and sensitivity results have been reported to be negative in about 40–75% of cases of discospondylitis in dogs, with percutaneous disc aspiration yielding positive culture in 75% of dogs.2,3,14,15 A definitive diagnosis of discospondylitis in dogs is therefore based on characteristic imaging findings in conjunction with compatible clinical signs, ideally in the presence of a positive culture result.2,5,16
MRI is considered the investigative method of choice in the diagnosis of discospondylitis in both people and dogs. It is considered more sensitive and specific than other imaging techniques, particularly in the early stages of the condition, being able to identify cases not evident on conventional radiographs.4–6,17 There is limited literature reporting diagnostic imaging findings of discospondylitis in cats, particularly with reference to cross-sectional imaging.
The aim of this retrospective study is to describe the MRI features of discospondylitis in a population of clinically affected cats. Radiography and CT features are discussed and compared with MRI when available, in order to give stronger guidance for the imaging diagnosis of feline discospondylitis.
Materials and methods
Animals
The medical records of cats diagnosed with both presumptive and confirmed discospondylitis at three referring institutions between February 2009 and April 2019 were reviewed.
Cases were included when they presented with: (1) clinical signs and history compatible with discospondylitis; and (2) MRI features suggestive of infection in one or more intervertebral discs, alone or in conjunction with its adjacent endplates. Compatible clinical signs included a persistent presence of spinal hyperaesthesia in all cases, lameness, abnormalities on neurological examination and pyrexia. As no extensive literature is available for MRI features of feline discospondylitis, an MRI diagnosis was based on previously reported imaging characteristics of discospondylitis in a single feline case report and in two case series of affected dogs.4,6,12 An MRI diagnosis of discospondylitis was considered when conformation or signal intensity of an intervertebral disc space (IVDS) differed, when compared with their adjacent counterparts. The finding of adjacent vertebral endplates with an abnormal conformation or signal intensity also supported the presence of a discospondylitis. All cases presenting an ongoing suspected or proven neoplastic process and history of trauma were excluded.
Imaging
Cross-sectional imaging was performed under general anaesthesia. All cats underwent CT using a multi-slice CT machine (Aquilion RXL; Toshiba Medical Systems) and MRI using a low-field 0.25 Tesla (T) permanent magnet (Esaote VetMR Grande), a low-field 0.4 T (Aperto MRI; Hitachi) or a high-field 1.5 T (Signa HDe; General Electric). MRI studies included a minimum of T2-weighted (T2W) sagittal and transverse images in all cases, a pre- and post-contrast T1-weighted (T1W) and/or short tau inversion recovery (STIR) dorsal, transverse or sagittal images in the remaining cases. Radiographic and CT studies were retrieved and assessed when available.
MRI features
MRI features were assessed, with selection of these features being based on reports on canine discospondylitis and a single feline report.4,6,12 The IVDS, nucleus pulposus, adjacent endplates, vertebral bodies, overlying epidural space, overlying meninges, paraspinal soft tissues and distal colon were all assessed. The MRI features assessed are described in Table 1. The epidural space was assessed for the presence of suspected empyema or suspected inflammation of the epidural fat.4,18 Overlying meninges were only assessed when high-field images were available, as it was considered that low-field images did not offer enough resolution to perform this in detail. The presence of a suspected paraspinal soft tissue abscessation was determined when a focal, well-demarcated region, presenting a contrast-enhancing rim pattern with an iso-hypointense centre in T2W sequences was detected in direct contact with the affected IVDS. 19 Colonic distension was considered subjectively normal or enlarged. Megacolon was considered if the ratio of maximum colonic diameter compared with the length of L5 was >1.48. 20 When evidence of discospondylitis was found on MRI then available radiographic and CT studies of the affected sites were evaluated.
MRI features assessed
IVDS = intervertebral disc space; T2W = T2-weighted; T1W = T1-weighted; STIR = short tau inversion recovery
Radiographic features
For each case, vertebral radiographs were evaluated if at least a lateral and a ventro-dorsal projection were available. Assessed features included evidence of endplate erosion, endplate sclerosis, vertebral body osteolysis, IVDS morphology (normal, narrowed or collapsed), osseous proliferation adjacent to the IVDS, spondylosis and soft tissue opacity alterations, as well as any signs of vertebral fracture, subluxation or shortening.4,5,7–10,12 The presence of the vacuum phenomenon was evaluated and the vertebral region surveyed was noted. 21
CT features
Vertebral CT images were evaluated and assessed features included evidence of endplate erosion, vertebral body osteolysis and its pattern (focal or multifocal punctate osteolysis), IVDS morphology (normal, narrowed or collapsed), osseous proliferation adjacent to the IVDS, endplate sclerosis, spondylosis, soft tissue attenuation alterations and signs of vertebral fracture, subluxation or shortening.7,14,22 The presence of the vacuum phenomena was evaluated and the vertebral region surveyed was noted.
Image assessment and imaging modality comparison
All radiographs and CT and MRI scans were assessed by two of the authors (SG and ML) independently. When an initial agreement was not attained, features were subsequently re-evaluated and a consensus was reached.
Descriptive comparison of the three modalities was performed, detailing cases where more than one modality was performed. In order to assess the capability of both radiography and CT in detecting feline discospondylitis when compared with MRI, it was considered that at least two radiological or CT features had to be identified in order for discospondylitis to be suspected based on these imaging modalities alone (eg, a narrowed/collapsed IVDS, as well as eroded endplates).
Follow-up
All follow-up repeated imaging studies in all modalities were retrieved, if available, and described in detail. Resolution of radiological signs was considered if the lytic focus had smoothed and disappeared, sclerotic margins had vanished and bridging of the affected vertebrae was detected on follow-up radiographs. 3
Results
Signalment
Thirteen cats were identified with a clinical diagnosis of discospondylitis. Breed distribution was as follows: domestic shorthair (n = 10), Maine Coon (n = 2) and Siamese (n = 1). There were five females and eight males, with a mean age of 9.1 years (median 9.4 years, range 1–14 years).
Fourteen foci of discospondylitis were identified in the 13 cats, with a single case presenting with two affected sites. Discospondylitis was identified at L7–S1 in 7/14 (50%), with T12–T13, T13–L1, L1–L2, L2–L3, L3–L4, L5–L6 and L6–L7 being represented once. In the case with two affected sites these were L1–L2 and L5–L6.
MRI findings
High-field MRI was available for six cases and low-field MRI in the remaining seven cases, encompassing eight sites of discospondylitis. Within the 14 imaged sites, one case had no T1W sequences; in another case, STIR sequences were not obtained, and in three cases undergoing low-field MRI, a contrast study was not performed. The signal intensity and contrast-enhancement features on MRI are detailed in Table 2.
IVDS morphology was assessed as normal (n = 6/14 [43%]), narrowed (n = 6/14 [43%]) or collapsed (n = 2/14 [14%]). There was no evidence of a concomitant disc herniation. Adjacent vertebral endplates were considered normal in 3/14 (21%), eroded in 7/14 (50%) and destroyed in 4/14 (29%). Vertebral body involvement was found in 6/14 cases and this was only found to affect a maximum of a third of the vertebral body. Evidence of vertebral body shape deformity was found in three cases and vertebral body subluxation was identified in one case. The epidural space was considered to be involved in five sites with a suspicion of either an empyema or a local inflammation of the epidural fat with a focal contrast enhancement in 3/5 sites. Compression of the spinal cord was present in 5/14 sites (36%), subjectively classified as mild in four cases and severe in the remaining case. Concomitant nerve root compression was observed in three cases. A region compatible with a suspected abscess in the paraspinal tissues was found in three cases (21%). Ventral spondylosis deformans was found in 10/14 cases, and the colon was considered subjectively enlarged in 10/13 cats, with two presenting imaging features compatible with megacolon. Examples of the MRI appearance of feline discospondylitis are depicted in Figure 1.
Overview of the MRI signal intensity features of feline discospondylitis found in this study
The most frequent finding in each category
T2W = T2-weighted; T1W = T1-weighted; STIR = short tau inversion recovery
Three examples of feline discospondylitis on sagittal plane MRI. (a) Discospondylitis present at L3–L4 (arrow) acquired on high-field MRI: A1 = T2-weighted; A2 = T1-weighted pre-contrast; A3 = T1-weighted post-contrast. (b) Discospondylitis present at T12–T13 (arrow) acquired on low-field MRI: B1 = T2-weighted; B2 = T1-weighted pre-contrast; B3 = T1-weighted post-contrast. (c) Discospondylitis present at L2–L3 (arrow) acquired on high-field MRI: C1 = T2-weighted; C2 = T1-weighted pre-contrast; C3 = T1-weighted post-contrast
Radiographic findings
Radiographs were available in four cases covering five discospondylitis sites. All radiographs were performed concurrently with initial MRI studies, except in one case covering two sites, which was performed 2 weeks previously. The lumbar region was included in all cases, with the whole vertebral column being radiographed in one case. Other cases surveyed the full thoracic spine to the tail (n = 1), the thoracolumbar junction to the tail (n = 1) and from C3 to the tail (n = 1). Evidence of endplate erosion alongside vertebral body osteolysis was found in 3/5 sites (60%), IVDS was abnormal in 4/5 sites, being narrowed in two and collapsed in the other two. A single occurrence was found of the following findings: endplate sclerosis, spondylosis, soft tissue opacity, vertebral body shortening and vertebral body subluxation. No osseous proliferation adjacent to the IVDS, vertebral body fractures or vacuum phenomena were identified. Based on these features, clear evidence of discospondylitis was only found in 3/5 sites (60%). Examples of the radiographic appearance of feline discospondylitis are given in Figure 2.
Two examples of feline discospondylitis identifiable on radiography. (a) L2–L3 discospondylitis (arrow): A1 = lateral projection; A2 = ventrodorsal projection. There is loss of normal endplate morphology, left lateral bone proliferation (arrow) and intervertebral disc space narrowing–endplate erosion with evidence of a reduced foramen at this level confirms a narrower space in comparison with adjacent spaces. (b) L7–S1 discospondylitis (arrow): B1 = lateral projection; B2 = ventrodorsal projection. There is endplate destruction and sclerosis, evidence of subluxation, osteolytic lesion at the S1 vertebral body and collapse of the intervertebral disc space at this level. A subjectively enlarged distal colon is also identifiable (*)
CT findings
CT was performed in two cases covering three discospondylitis sites. In one case the whole vertebral column was imaged, while the other included the area of interest encompassing T7 to the tail. Evidence of endplate erosion was present in one case (33%) and IVDS morphology was considered normal in one site and collapsed in the other two sites (66%). A single occurrence was found of the following findings: endplate sclerosis, spondylosis deformans and vacuum phenomena within the affected intervertebral disc. No evidence of soft tissue attenuation, osseous proliferation, vertebral body osteolysis, shortening, fractures or subluxations were identified. Based on these features, clear evidence of discospondylitis was only found in 1/3 sites (33%) (Table 3). Examples of CT appearance of feline discospondylitis are given in Figure 3.
Comparison of different imaging modalities in the available cases
Two examples of feline discospondylitis identifiable on CT. (a) L5–L6 discospondylitis (arrow): A1 sagittal plane, A2 dorsal plane. Narrowing of the intervertebral disc space is identifiable without endplate erosion. (b) L7–S1 discospondylitis (arrow): B1 sagittal plane, B2 dorsal plane. There is endplate sclerosis, collapse of the intervertebral disc space and evidence of spondylosis deformans ventral to the affected disc. A subjectively enlarged distal colon is also identifiable (*)
Comparison of imaging modalities
When comparing radiographic and MRI findings in five available sites (Table 3), two sites were not clearly apparent radiographically; although one of the disc spaces was collapsed, no evidence of endplate erosion or other associated features were identifiable in either of them. This occurred in the case in which two discospondylitis foci were identified on MRI, which was the only case where the three imaging modalities were performed. Radiographs in this case were performed 2 weeks previous to the MRI study. In these sites, the nucleus pulposus was T2W isointense and STIR hyperintense, with diffuse contrast enhancement, and paraspinal tissues were also involved, being hyperintense on both T2W and STIR sequences. Also CT, performed at the time of MRI diagnosis, did not suggest discospondylitis owing to the lack of endplate or vertebral body changes. Radiographs provided indication of three discospondylitis sites out of five, by revealing a combination, among other features, of signs of endplate erosion, as well as narrowing or collapse of the affected IVDS. None of these later cases had CT performed.
In the second case in which CT was performed, there was clear evidence of endplate erosion, a collapsed IVDS, endplate sclerosis, evidence of subluxation and ventral spondylosis deformans (Figure 3b). This was further confirmed on MRI in which a T2W hyperintense nucleus pulposus with rim-contrast enhancement was identified, with a third of the vertebral body affected.
Follow-up
Repeated imaging studies were only available for one case, in which radiography was repeated 6 and 9 months after diagnosis and a treatment protocol with antibiotics was initiated (Figure 4). Radiological resolution was not present: there was radiographic evidence of disappearance and smoothing around a lytic focus, and partial replacement by bridging of the involved vertebrae; however, sclerotic margins were still detectable on both follow-up radiographs.
L7–S1 feline discospondylitis identifiable on repeated radiography following treatment with antibiotics: A1 (initial); A2 (6 months later); A3 (9 months later). Full radiological resolution was not present, despite clinical resolution
Discussion
This report describes the MRI features of discospondylitis in a population of cats, including its comparison with radiography and CT, when available. This study revealed a series of imaging features that could aid in the detection of discospondylitis in cats.
Feline discospondylitis had been previously reported in six individual case reports and two cats being described in a series of feline patients with spinal cord disease.7–13 Previously reported affected disc spaces in these cats were L7–S1 (n = 3), L3–L4 (n = 2), L4–L5 (n = 2) and L2–L3 (n = 1), with two cats presenting multiple affected discs. This study confirms the suspicion that L7–S1 appears to be an intervertebral disc particularly susceptible to discospondylitis in cats, making up 50% of our reported population and contributing almost half of the total of reported cases. The L7–S1 IVDS is also described as the most commonly affected site in dogs.2–4 We also report the first two instances of feline thoracic discospondylitis (T12–T13 and T13–L1).
MRI features of discospondylitis in dogs have been described previously and have been found to be generally consistent, although individual variability has been reported.4–6 In the sole feline discospondylitis report with MRI findings, the intervertebral disc was T2W hyperintense and T1W isointense, and the vertebral endplates were T2W and T1W hypointense. 12 Marked contrast enhancement of the L7 and S1 endplates and surrounding soft tissues was evident. A subjectively distended distal colon was also reported. 12
Magnetic resonance features of discospondylitis in cats appeared to be fairly consistent within the population described in this study, although individual variability was apparent. IVDS morphology was altered in 57% of cases. Nucleus pulposus signal was found to be mainly hyperintense on both T2W and STIR sequences with signal void occasionally seen on T2W images. T1W sequences were typically isointense; contrast uptake was noticeable in every case where this was available. Affected vertebral endplates were irregularly eroded or completely destroyed. Vertebral bodies were mostly unaffected, with the majority failing to enhance after intravenous contrast injection. The neighbouring soft tissues were often abnormal, with T2W and STIR hyperintensity and contrast enhancement present in every case where this was available. These MRI findings were mostly compatible with the MRI features described for dogs.4–6 In contrast, epidural space involvement and compression of the spinal cord or nerve roots were found in 36% of cases (n = 5/14), which differs from dogs, where both were found more commonly.4,6 Overlying meningeal signal intensity abnormalities were common, with contrast enhancement present in all five cases, indicating that discospondylitis in cats relates to a secondary focal meningitis. Other findings were the presence of areas compatible with paraspinal abscessation in 21% of cases and a high prevalence of ventral spondylosis deformans (71%).
Radiographic features previously described in feline patients include vertebral endplate lysis and/or sclerosis, a narrowed or collapsed IVDS, spondylosis deformans, irregular bone proliferation ventrally to the affected disc, an increase in ventral soft tissue opacity and subluxation at the level of the L7–S1 joint. All of these features, except for bone proliferation, were found in our population of cats. Vertebral body shortening is a new feature associated with discospondylitis in our subset of patients. The most common radiographic feature was collapse or narrowing of the affected IVDS (80%), with endplate erosion seen in 60% of radiographs. Radiographic evidence of IVDS narrowing has been reported in cats suffering from other conditions such as intervertebral disc disease and acute non-compressive nucleus pulposus extrusion.23–25 However, when evidence of intervertebral disc space narrowing is identified in a cat with spinal hyperaesthesia, particularly in the presence of endplate erosion, discospondylitis should be included in the list of differential diagnoses. Interestingly, in one of the cases previously reported, discospondylitis was identified post mortem, and had not been identified on either survey radiographs or myelography. 11 In our population there were two affected sites in which radiography and CT failed to reveal characteristics relating to discospondylitis when changes were present on MRI. In dogs, there is a reported delay in the development of radiographic signs, with additional cross-sectional imaging often necessary to make a diagnosis. 5 The presence of discospondylitis with minimal or no changes on radiographs and CT would support the same assertion in feline patients. However, further cases might be required to confirm this in view of the small number of cases having been investigated using all imaging modalities.
CT findings of discospondylitis in both cats and dogs include the same features as plain radiography with the addition of being able to identify areas of punctate osteolysis within the endplates with or without osteolysis of the adjacent bone.7,14,22 In one previously reported cat, contrast CT identified a rim contrast-enhanced mass compatible with an abscess next to the affected disc. 7 CT has clear advantages over plain radiography, offering a more detailed depiction of bone with the potential of identifying osseous lesions earlier in the course of disease. 5 However, in one of our cases there was a time lapse of 2 weeks between radiography and both CT and MRI. In this case, there was no evidence of changes on radiography besides a reduced IVDS. An argument could be made that radiological features had not yet developed; however, CT performed at the same time as MRI also failed to detect radiological features supportive of discospondylitis (A1 and A2 in Figure 3). In our population of cats, CT findings were compatible with previous reports, with a reduced intervertebral disc space being the most repeatable finding. Interestingly, the vacuum phenomenon was identified within one of the affected intervertebral discs. This is a radiographic feature most commonly associated with intervertebral disc extrusion. 26 This is the first reported occurrence of this sign in a feline discospondylitis patient, although it has previously been reported in canine discospondylitis. 21 Although radiography lacked sensitivity for the detection of discospondylitis, CT also failed to identify discospondylitis detected on MRI in 2/3 imaged sites. Further studies utilising CT in feline discospondylitis would be required to further assess its potential diagnostic value.
The presence of infectious processes of the vertebral column in cats, such as empyema, has previously been reported in cats in the absence of a concurrent discospondylitis.27–30 Feline discospondylitis, however, has been reported concomitantly to paravertebral abscesses and meningomyelitis.7,9,11 Within our population, the subset of patients presenting contrast-enhancing regions within the epidural space, meninges or paraspinal soft tissues could have presented with abscessation or even meningomyelitis. When such regions were identified in the epidural space, these were considered to either be a sign of an empyema or inflammation of the epidural fat. The presence of these concomitant and adjacent infectious loci could be explained by the close proximity of these structures allowing direct spread of an infectious agent.
Imaging evidence of a subjectively enlarged colon was found in the majority of cases, with megacolon found in 15%. Although some faecal retention is to be expected in cases presenting with spinal pain, the clinical significance of this later finding is unknown. Further clarification would require studies describing clinical presentation and treatment of feline discospondylitis and other spinal cord disorders.
Follow-up imaging was only available in one case with repeated radiographs at 6 and 9 months following diagnosis. In dogs, evidence of radiological resolution of discospondylitis was only achieved after treatment for a period of 53.7 ± 45.4 weeks. 3 In our case, there was evidence of a partial resolution of the radiological signs at 9 months. Further studies will be required to demonstrate if radiological resolution in the feline population is similar to that reported in dogs. Follow-up cross-sectional imaging, particularly MRI, may have the potential to predict clinical resolution, treatment length and relapse in both feline and canine discospondylitis.
A number of limitations exist in the current study. Data were collected retrospectively, and therefore imaging acquisition protocols and equipment were not standardised. Diagnosis of discospondylitis relied on clinical features and MRI evidence of a suspected infectious process affecting the IVDSs and/or the vertebral endplates. Therefore, MRI was used as an inclusion criteria and it could therefore not be compared in terms of sensitivity and specificity with the other imaging modalities. There may have been cases in which MRI did not reveal any changes where a diagnosis of discospondylitis could have been missed. However, imaging is critical in making a diagnosis of discospondylitis and even if no abnormalities are found at an initial MRI, these should develop as the condition progresses. 5 A full vertebral column study was not performed in most cases, leaving the potential for other affected intervertebral discs being overlooked. This can be explained by costs associated with advanced imaging and investigation based on an area of interest identifiable either through a clear neurolocalisation or an indication of a neurolocalisation based on spinal hyperaesthesia. We would recommend that when a focus of discospondylitis is detected, imaging of the entire vertebral column is performed in search of other possible foci of infection. Only a small number of radiographs and CT studies were available in relation with MRI studies, which limited comparison within modalities. Follow-up study was only available in one case and further information could have been gathered with an increased number of cases.
Conclusions
This is the largest reported population of cats diagnosed with discospondylitis. A set of MRI features are described, indicating a series of consistent findings that might be helpful in the diagnosis of discospondylitis in cats. Although only a few cases had all imaging modalities performed, the findings in this study support the notion that MRI should be considered the investigation method of choice in the diagnosis of discospondylitis in feline patients, as is presently considered in both dogs and humans. Where only radiography is available, evidence of IVDS narrowing in conjunction with adjacent endplate irregularities should be considered a strong indication for the presence of discospondylitis, and further advanced imaging should be performed.
Footnotes
Conflict of interest
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Ethical approval
This work involved the use of client-owned animal(s) only, and followed established internationally recognised high standards (‘best practice’) of individual veterinary clinical patient care. Ethical approval from a committee was therefore not necessarily required.
Informed consent
Informed consent (either verbal or written) was obtained from the owner or legal custodian of all animal(s) described in this work for the procedure(s) undertaken. No animals or humans are identifiable within this publication, and therefore additional informed consent for publication was not required.
