Vet Comp Orthop Traumatol 2021; 34(03): 191-199
DOI: 10.1055/s-0040-1721375
Original Research

Thoracic Vertebral Canal Stenosis Associated with Vertebral Arch Anomalies in Small Brachycephalic Screw-Tail Dog Breeds

Alessandro Conte
1   Torrington Orthopaedics, Brighouse, United Kingdom
Marco Bernardini
2   Ospedale Veterinario “I Portoni Rossi”, Zola Pedrosa, Italy
3   Department of Animal Medicine, Production and Health, University of Padova, Legnaro, Italy
Steven De Decker
4   Royal Veterinary College, University of London, Hatfield, United Kingdom
Cristoforo Ricco
5   Willows Veterinary Centre & Referral Service, Solihull, United Kingdom
Sebastien Behr
5   Willows Veterinary Centre & Referral Service, Solihull, United Kingdom
Daniel Sanchez-Masian
6   Anderson Moores Veterinary Specialists, Winchester, United Kingdom
Guinio B. Cherubini
7   Dick White Referrals, Six Mile Bottom, United Kingdom
Luisa De Risio
8   Linnaeus Group, Shirley, United Kingdom
9   Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
› Author Affiliations


Objective The aim of this study was to describe clinical and imaging features of thoracic vertebral canal stenosis secondary to the hypertrophy of the vertebral lamina and articular processes in screw-tail brachycephalic dog breeds, to evaluate the prevalence of the malformation in a large group of screw-tail dog breeds and to determine if degree of stenosis is associated with presence of neurological signs.

Study Design This is a retrospective multicentric study.

Materials and Methods Clinical records of 185 screw-tail brachycephalic dogs (French Bulldogs, English Bulldogs, Boston Terriers) and Pugs were reviewed. Ten dogs with neurological deficits secondary to thoracic vertebral canal stenosis diagnosed on magnetic resonance imaging were identified (Group 1). Neurologically normal dogs (n = 175) of the same breeds underwent computed tomographic imaging of the thoracic vertebral column for other medical reasons (Group 2). Cross-sectional measurements were used to calculate a stenotic ratio.

Results Group 1 consisted of three French Bulldogs, six English Bulldogs and one Pug. Eight were males. Most dogs presented with progressive non-painful pelvic limbs ataxia and paresis. Twenty stenotic sites were identified with the most common being T4–T5. Three of ten dogs were treated surgically and all had a good long-term outcome. In Group 2, 33 of 175 dogs had one or more stenotic sites with the most common being T2–T3. The degree of the stenosis was significantly higher in Group 1 (p = 0.019). A stenotic ratio of 0.56 had sensitivity and specificity of 67% to differentiate between dogs with and without neurological signs.

Conclusion Cranial thoracic vertebral canal stenosis is observed predominantly in young male Bulldogs, but not all stenoses are clinically relevant.


Preliminary results of this study were presented as an oral presentation at BSAVA Annual Scientific Meeting, April 4–7, 2019, Birmingham, UK.

Authors' Contributions

A.C. and R.G. designed the study. R.G. contributed to conceptualization of the study. A.C., M.B., S.D., C.R., S.B., D.S., G.C., L.D. and R.G. contributed to acquisition of data and data analysis and interpretation. They drafted, revised and approved the submitted manuscript. All the authors are publically accountable for relevant content.

Supplementary Material

Publication History

Received: 13 March 2020

Accepted: 15 October 2020

Article published online:
07 December 2020

© 2020. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

  • References

  • 1 Stigen Ø, Hagen G, Kolbjornsen Ø. Stenosis of the thoracolumbar vertebral canal in a basset hound. J Small Anim Pract 1990; 31: 621-623
  • 2 Stalin CE, Pratt JN, Smith PM, Jeffery ND. Thoracic stenosis causing lateral compression of the spinal cord in two immature Dogues de Bordeaux. Vet Comp Orthop Traumatol 2009; 22 (01) 59-62
  • 3 Johnson P, De Risio L, Sparkes A, McConnell F, Holloway A. Clinical, morphologic, and morphometric features of cranial thoracic spinal stenosis in large and giant breed dogs. Vet Radiol Ultrasound 2012; 53 (05) 524-534
  • 4 Hecht S, Michaels J, Childers S. et al. Cranial thoracic stenotic spondylomyelopathy in a young Rottweiler. Vet Rec Case Rep 2017; 5: 1-2
  • 5 Miller A, Marchevsky A. Cranial thoracic vertebral canal stenosis in three juvenile large-breed brachycephalic dogs treated by unilateral hemilaminectomy. Vet Comp Orthop Traumatol 2017; 30 (03) 223-229
  • 6 Westworth DR, Sturges BK. Congenital spinal malformations in small animals. Vet Clin North Am Small Anim Pract 2010; 40 (05) 951-981
  • 7 Gutierrez-Quintana R, Guevar J, Stalin C, Faller K, Yeamans C, Penderis J. A proposed radiographic classification scheme for congenital thoracic vertebral malformations in brachycephalic “screw-tailed” dog breeds. Vet Radiol Ultrasound 2014; 55 (06) 585-591
  • 8 Steffen F, Berger M, Morgan JP. Asymmetrical, transitional, lumbosacral vertebral segments in six dogs: a characteristic spinal syndrome. J Am Anim Hosp Assoc 2004; 40 (04) 338-344
  • 9 Wrzosek M, Płonek M, Zeira O, Bieżyński J, Kinda W, Guziński M. Congenital bipartite atlas with hypodactyly in a dog: clinical, radiographic and CT findings. J Small Anim Pract 2014; 55 (07) 375-378
  • 10 Ryan R, Gutierrez-Quintana R, Ter Haar G, De Decker S. Prevalence of thoracic vertebral malformations in French bulldogs, Pugs and English bulldogs with and without associated neurological deficits. Vet J 2017; 221: 25-29
  • 11 Wheeler SJ. Vertebral abnormalities in dogs. J Small Anim Pract 1991; 32: 149-150
  • 12 Knecht CD, Blevins WE, Raffe MR. Stenosis of the thoracic spinal canal in English Bulldogs. J Am Anim Hosp Assoc 1979; 15: 181-183
  • 13 Ryan R, Gutierrez-Quintana R, Haar GT, De Decker S. Relationship between breed, hemivertebra subtype, and kyphosis in apparently neurologically normal French Bulldogs, English Bulldogs, and Pugs. Am J Vet Res 2019; 80 (02) 189-194
  • 14 Youden WJ. Index for rating diagnostic tests. Cancer 1950; 3 (01) 32-35
  • 15 Breit S. Osteological and morphometric observations on intervertebral joints in the canine pre-diaphragmatic thoracic spine (Th1-Th9). Vet J 2002; 164 (03) 216-223
  • 16 Dabanoglu I, Kara ME, Turan E, Ocal MK. Morphometry of the thoracic spine in German shepherd dog: a computed tomographic study. Anat Histol Embryol 2004; 33 (01) 53-58
  • 17 Parker HG, Dreger DL, Rimbault M. et al. Genomic analyses reveal the influence of geographic origin, migration and hybridization on modern dog breed development. Cell Reports 2017; 19 (04) 697-708
  • 18 Pedersen NC, Pooch AS, Liu H. A genetic assessment of the English bulldog. Canine Genet Epidemiol 2016; 3: 6
  • 19 Fisher SC, Shores A, Simpson ST. Constrictive myelopathy secondary to hypoplasia or aplasia of the thoracolumbar caudal articular processes in Pugs: 11 cases (1993-2009). J Am Vet Med Assoc 2013; 242 (02) 223-229
  • 20 Full A, Dewey C, Bouma J. Prevalence and magnetic resonance imaging of intervertebral disc disease in pugs with caudal articular facet dysplasia of the thoracolumbar spine. Vet Radiol Ultrasound 2014; 55: 681
  • 21 Ballegeer E, Patterson J, Paese A. et al. Incidence of vertebral anomalies in Pug dogs; implications for myelopathies?. Vet Radiol Ultrasound 2015; 57: 93
  • 22 Bertram S, Ter Haar G, De Decker S. Caudal articular process dysplasia of thoracic vertebrae in neurologically normal French bulldogs, English bulldogs, and Pugs: Prevalence and characteristics. Vet Radiol Ultrasound 2018; 59 (04) 396-404
  • 23 da Costa RC. Cervical spondylomyelopathy (Wobbler syndrome) in dogs. Vet Clin N Am-Small 2010; 40: 881-913
  • 24 Trotter EJ, deLahunta A, Geary JC, Brasmer TH. Caudal cervical vertebral malformation-malarticulation in Great Danes and Doberman Pinschers. J Am Vet Med Assoc 1976; 168 (10) 917-930
  • 25 De Decker S, Gielen IM, Duchateau L, Polis I, Van Bree HJ, Van Ham LM. Agreement and repeatability of linear vertebral body and canal measurements using computed tomography (CT) and low field magnetic resonance imaging (MRI). Vet Surg 2010; 39 (01) 28-34