Review proposes spectrum model for canine spinal meningeal disease
Bottom line
A new mini-review in Frontiers in Veterinary Science argues that spinal arachnoid diverticula and constrictive myelopathy in dogs may be better understood not as fully separate disorders, but as points along a broader spectrum of spinal meningeal disease. The paper, published in 2026 by João Miguel De Frias and colleagues, draws parallels with human neurology, where related entities such as arachnoid cysts, arachnoid webs, adhesive arachnoiditis, and idiopathic spinal cord herniation are already described as distinct but overlapping meningeal disorders. The authors propose a unifying term, “spinal meningeal adhesive disease,” to help frame canine cases that may share mechanisms involving adhesions, fibrosis, and disrupted cerebrospinal fluid flow. (frontiersin.org)
Why it matters: For veterinary professionals, the review pushes on a familiar diagnostic boundary. Spinal arachnoid diverticula have long been recognized in dogs, while constrictive myelopathy, especially in pugs, has emerged more recently and has been linked to pia-arachnoid fibrosis, circumferential cord constriction, and loss of normal CSF signal on MRI. Reframing these presentations as a spectrum could influence how neurologists interpret advanced imaging, discuss pathogenesis with pet parents, and think about surgical planning, prognosis, and recurrence, particularly in breeds already overrepresented for meningeal and thoracolumbar spinal disease. (pmc.ncbi.nlm.nih.gov)
What to watch: Watch for whether the proposed terminology gains traction in referral neurology, imaging reports, and future outcome studies that compare dogs currently labeled with SAD versus constrictive myelopathy. (frontiersin.org)
Key facts
- Journal
- Frontiers in Veterinary Science
- Article type
- Mini-review
- Publication year
- 2026
- Authors
- João Miguel De Frias and colleagues
- Main proposal
- Spinal arachnoid diverticula and constrictive myelopathy may be part of a broader spinal meningeal disease spectrum
- Proposed term
- Spinal meningeal adhesive disease
- Human parallels
- Arachnoid cysts, arachnoid webs, adhesive arachnoiditis, and idiopathic spinal cord herniation
- Shared mechanisms
- Adhesions, fibrosis, and disrupted cerebrospinal fluid flow
A newly published comparative review in Frontiers in Veterinary Science is asking veterinary neurology to reconsider a long-standing divide: whether spinal arachnoid diverticula and constrictive myelopathy in dogs are truly different diseases, or part of the same meningeal disorder spectrum. The 2026 paper by João Miguel De Frias and co-authors argues that canine cases may align more closely with the broader framework already used in human medicine, and introduces “spinal meningeal adhesive disease” as a unifying diagnostic concept. (frontiersin.org)
That proposal builds on an uneven history in the literature. Spinal arachnoid diverticula, sometimes described in older literature as subarachnoid diverticula or intradural arachnoid diverticula, have been documented in dogs for decades as focal dilations of the subarachnoid space that can cause progressive compressive myelopathy. A 2020 review noted that pugs, French bulldogs, and Rottweilers are overrepresented, and that affected dogs commonly present with ataxia, paresis, and sometimes urinary or fecal dysfunction. By contrast, constrictive myelopathy has been characterized more recently, particularly in pugs, as a circumferential fibrotic lesion with impaired CSF flow rather than a simple focal dilation. (pmc.ncbi.nlm.nih.gov)
The new review’s core argument is comparative. In humans, several related spinal meningeal disorders are recognized, including intradural or extradural arachnoid cysts, spinal arachnoid web, spinal adhesive arachnoiditis, and idiopathic spinal cord herniation. De Frias and colleagues argue that canine SAD and constrictive myelopathy may map onto parts of that same disease family, with overlapping pathology centered on adhesions, fibrosis, and altered CSF dynamics. The paper was accepted on June 15, 2026, and published about three weeks later as part of Frontiers’ veterinary neurology and neurosurgery section. (frontiersin.org)
Recent related reports support the idea that these categories may blur in practice. A 2025 Frontiers case report on long-term surgical outcomes in pug dogs with articular facet dysplasia-associated thoracolumbar myelopathies described constrictive myelopathy, also termed pia-arachnoid fibrosis, as a focal circumferential lesion with absent subarachnoid CSF signal on T2-weighted MRI and thickened pia-arachnoid bands that are best seen on 3D-CISS imaging. That report also noted a hypothesis that chronic micromotion or instability in high-mobility thoracolumbar regions may contribute to lesion development, especially in pugs. Separate imaging work has linked thoracic caudal articular process dysplasia with constrictive myelopathy in that breed, reinforcing the idea that anatomy, biomechanics, and meningeal pathology may interact. (frontiersin.org)
The broader canine literature also shows why a spectrum model may be attractive. Prior reviews and retrospective studies have described SAD as heterogeneous in location, conformation, treatment approach, and outcome, with recurrence and persistent deficits remaining concerns after surgery in some dogs. More recent microsurgical case series suggest technical refinements may improve short-term neurologic outcomes, but they don’t settle the underlying nosology. In other words, clinicians may already be treating a family of related meningeal disorders under different labels. That is an inference, but it is consistent with the pattern described across the review and prior studies. (pmc.ncbi.nlm.nih.gov)
Why it matters: For veterinary professionals, the paper’s real value is not just semantics. If SAD and constrictive myelopathy sit on a continuum, then case workups may need to focus more explicitly on meningeal adhesions, fibrosis, and CSF flow disruption, not simply on whether imaging shows a classic diverticular dilation. That could affect MRI protocol choices, interpretation of advanced sequences, surgical decision-making, and client communication about uncertainty, recurrence risk, and expected outcomes. It may also encourage more standardized reporting across referral centers, which has been a challenge in the existing literature. (pmc.ncbi.nlm.nih.gov)
There does not yet appear to be substantial outside commentary on this specific review, likely because it was published only recently. Still, the author group itself carries weight in veterinary neurology, spanning the University of Edinburgh, Ghent University, AniCura Albano, and the Royal Veterinary College, and the paper fits into an active stream of Frontiers publications on canine meningeal and thoracolumbar myelopathies. (frontiersin.org)
What to watch: The next signal will be whether future retrospective series, consensus statements, or imaging studies adopt “spinal meningeal adhesive disease” and test whether dogs currently split into SAD and constrictive myelopathy groups actually differ in pathology, treatment response, or long-term outcome. (frontiersin.org)