Review proposes unified term for canine spinal meningeal disease
Bottom line
A new comparative review in Frontiers in Veterinary Science argues that spinal arachnoid diverticula and constrictive myelopathy in dogs may be better understood as part of the same disease spectrum, rather than as fully separate entities. The July 6, 2026 paper, led by João Miguel De Frias and colleagues from the University of Edinburgh, Royal Veterinary College, Ghent University, AniCura Albano, and a human neurosurgery collaborator in Edinburgh, proposes the umbrella term spinal meningeal adhesive disease for these spinal meningeal disorders. The authors say the current split in terminology can make diagnosis, case classification, and treatment selection harder, especially because imaging and pathology features often overlap. (frontiersin.org)
Why it matters: For veterinary professionals, the review is less about introducing a new treatment than about reframing how chronic, progressive thoracolumbar and cervical myelopathies are interpreted. Spinal arachnoid diverticula have been described in dogs for decades, while constrictive myelopathy was identified more recently, particularly in pugs. The review points to overlap between the two, including shared meningeal adhesions and the difficulty of distinguishing them on MRI alone. That could affect how neurologists, surgeons, and radiologists communicate findings, counsel pet parents, and think about prognosis, recurrence, and the role of concurrent vertebral abnormalities or multilevel disease. (frontiersin.org)
What to watch: Whether future clinical studies adopt the proposed terminology and test whether these cases truly share pathophysiology, imaging patterns, and treatment responses. (frontiersin.org)
Key facts
- Journal
- Frontiers in Veterinary Science
- Publication date
- July 6, 2026
- Lead author
- João Miguel De Frias
- Proposed umbrella term
- Spinal meningeal adhesive disease
- Conditions discussed
- Spinal arachnoid diverticula and constrictive myelopathy in dogs
- Core argument
- The review says the two conditions may be part of the same disease spectrum
- Key diagnostic issue
- Imaging and pathology features often overlap, making diagnosis and classification harder
- Notable breed context
- Constrictive myelopathy was first described in pugs
A newly published mini-review in Frontiers in Veterinary Science is making a terminology argument with practical implications: spinal arachnoid diverticula and constrictive myelopathy in dogs may not be distinct diseases so much as related expressions of a broader spinal meningeal disorder. Published July 6, 2026, the paper proposes the term spinal meningeal adhesive disease to unify conditions that affect the spinal meninges and can lead to progressive myelopathy. (frontiersin.org)
That proposal builds on a long and sometimes confusing history. The review notes that canine spinal arachnoid diverticula have been described for more than 50 years, under multiple names including meningeal cyst, arachnoid cyst, and subarachnoid diverticulum, before the field largely settled on spinal arachnoid diverticulum because these lesions lack a true epithelial lining. Constrictive myelopathy, by contrast, is a newer label, first described in pugs and also referred to in the literature as meningeal fibrosis or pia-arachnoid fibrosis. (frontiersin.org)
The authors' core argument is that the distinction between these diagnoses can be blurry in practice. In the review, they point to overlapping imaging and histopathologic findings, and to parallels with human spinal meningeal diseases such as intradural and extradural arachnoid cysts, arachnoid webs, adhesive arachnoiditis, and idiopathic spinal cord herniation. They also cite prior work showing that in pugs with meningeal fibrosis, MRI identified arachnoidal diverticulum formation in more than half of cases, reinforcing the idea that these may sit on a spectrum rather than in separate boxes. (frontiersin.org)
Outside the new review, the broader literature supports that overlap. A 2023 prospective study of 32 client-owned pugs with chronic progressive T3-L3 myelopathy found that constrictive myelopathy affected more than half of the dogs, and that most had multilevel disease, concurrent myelopathies, or both. Earlier work on thoracolumbar meningeal fibrosis in pugs likewise described a shared clinical phenotype with differing underlying lesions, while a 2024 study on canine spinal arachnoid diverticula highlighted variation in lesion conformation and its possible relevance to localization and outcome. Taken together, that body of work helps explain why a unifying framework may appeal to specialists managing these cases. (pubmed.ncbi.nlm.nih.gov)
The review does not claim the science is settled. Instead, it argues that a broader label could better reflect uncertainty while research catches up. The proposed term, abbreviated by the authors as SMADs, is intended to cover adhesive meningeal pathologies that may be idiopathic or secondary to an identified cause. The paper also emphasizes a One Health angle, suggesting that veterinary and human medicine face similar classification and treatment challenges in rare spinal meningeal disorders. (frontiersin.org)
Why it matters: For veterinary professionals, the immediate value is conceptual and clinical. A spectrum-based model may encourage more careful interpretation of MRI findings, especially because features such as the so-called scalpel-blade sign are not exclusive to one meningeal disorder. It may also support more nuanced case discussions around surgery, recurrence, and prognosis in dogs with chronic non-painful ataxia, paresis, incontinence, or mixed compressive lesions. Prior outcome data in dogs with spinal arachnoid diverticula already show that these are not straightforward cases, and the new review suggests some of that variability may reflect underlying disease heterogeneity rather than technical treatment differences alone. (frontiersin.org)
There are also breed and referral-practice implications. Because constrictive myelopathy has been especially associated with pugs, and because concurrent vertebral malformations and caudal articular process dysplasia often complicate thoracolumbar pug cases, a unified framework could sharpen how specialists classify overlapping pathology without overcommitting to a single mechanism too early. For general practitioners, that may eventually translate into clearer referral language and better expectation-setting for pet parents facing advanced imaging, surgery, or long-term management decisions. (pubmed.ncbi.nlm.nih.gov)
What to watch: The next step is whether future retrospective and prospective studies adopt the proposed terminology, correlate it with histopathology and imaging subtypes, and determine whether dogs grouped under this broader meningeal disease concept actually differ in treatment response or long-term outcome. (frontiersin.org)