Computed tomography features of discospondylitis in dogs

Abstract

Background Computed tomography (CT) findings of dogs with discospondylitis have not been widely described despite increased availability of this imaging modality. Objectives Describe the CT features of discospondylitis in a population of clinically affected dogs with discospondylitis diagnosed by magnetic resonance imaging (MRI). Animals Forty‐one dogs (63 affected discs) with MRI‐identified discospondylitis presented to a single referral hospital between 2012 and 2022. Methods Retrospective, single center, descriptive case series with analysis of MRI‐identified discospondylitis sites and concomitant CT imaging. Computed tomographic features of MRI‐affected sites including intervertebral disc space (IVDS), endplates, vertebral body, epidural space and paraspinal tissues were described. Results The most frequently found changes were: (1) endplate involvement (87.3%) most frequently bilateral (94.5%), with erosion (61.9%) and multifocal osteolysis (67.3%); (2) periosteal proliferation adjacent to the IVDS (73%) and spondylosis (66.7%); and (3) vertebral body involvement (66.7%) involving one‐third of the vertebra (85.7%) with multifocal osteolysis (73.5%). Other less prevalent features included an abnormal IVDS (narrowed or collapsed), sclerosis of the adjacent vertebral body or endplates, presence of disseminated idiopathic skeletal hyperostosis or vacuum artifact. Conclusions and Clinical Importance We determined that bilateral endplate erosion and periosteal proliferation were very common in dogs with discospondylitis. Careful evaluation of CT in all 3 planes (dorsal, sagittal, transverse) is necessary to identify an affected IVDS. These described CT features can aid in the diagnosis of discospondylitis in dogs but equivocal cases might still require MRI.

Clinical features, comparative imaging findings, treatment, and outcome in dogs with discospondylitis: A multi‐institutional retrospective study

“…While many studies have reported radiographic, CT, and MRI features of discospondylitis in dogs, data on comparative imaging findings is more limited 6,8,9,13,21 . In our study, a radiographic diagnosis of discospondylitis had a fair agreement with a CT diagnosis, but a reduced level of agreement with MRI.…”

“… 7 Characteristic CT features of discospondylitis included endplate erosion, osteolysis, and periosteal proliferation adjacent to the intervertebral disc spaces. 8 Characteristic MRI features of discospondylitis were STIR hyperintensity of the intervertebral discs and endplates, or endplates, contrast enhancement of the intervertebral discs, and increased T2 and decreased T1 signal intensity of soft tissues ventral to vertebral bodies. 4 , 9 , 10 All cases were diagnosed and managed by a board‐certified veterinary neurologist or an intern/resident under the guidance of a veterinary neurologist.…”

“…Characteristic radiographic features of discospondylitis included irregular endplate lysis with extension into the vertebral body, collapse of the intervertebral disc space, and sclerosis peripheral to the endplate lysis 7 . Characteristic CT features of discospondylitis included endplate erosion, osteolysis, and periosteal proliferation adjacent to the intervertebral disc spaces 8 . Characteristic MRI features of discospondylitis were STIR hyperintensity of the intervertebral discs and endplates, or endplates, contrast enhancement of the intervertebral discs, and increased T2 and decreased T1 signal intensity of soft tissues ventral to vertebral bodies 4,9,10 .…”

“…One hundred fifty were female (120 spayed and 30 intact females) and 236 were male (135 castrated and 101 intact males). The most common dog breed was mixed breed (70), followed by Labrador Retriever (50), German Shepherd Dog (34), Boxer (21), French Bulldog (14), Doberman Pinscher (13), English Bulldog (9), Great Dane (9), Golden Retriever (8), Rottweiler (7), Weimaraner (7), English Springer Spaniel (6), Staffordshire Bull Terrier (6), Welsh Corgi (5), Maltese (5), Mastiff (5), Miniature Pinscher (5), Dachshund (4), Miniature Schnauzer (4), Pit Bull (4), Shih Tzu (4), Toy Poodle (4), Vizsla (4), Yorkshire Terrier (4), Border Collie (3), Bulldog (3) Breeds significantly overrepresented in our study group, with ratios of breed as a proportion of the study group compared to the proportion of the AKC group occupied by the same breed, indicated by the term "ratio" were: Greyhound (ratio: 42.4, P < .001), Polish Lowland Sheepdog (ratio: 20.5, P < .001), Dandie Dinmont Terrier (ratio: 19.6, P < .001), Staffordshire Bull Terrier (ratio: 10.7, P < .001), English Setter (ratio: 42.4, P < .001), Briard (ratio: 7.5, P = .02), Irish Wolfhound (ratio: 4.2, P = .03), French Bulldog (ratio: 3.2, P < .001), Weimaraner (ratio: 2.5, P = .01), Doberman Pinscher (ratio: 2.1, P = .005), German Shepherd Dog (ratio: 1.4, P = .05), and Australian Cattle Dog (ratio: 1.3, P < .001). Breeds significantly underrepresented in our study group were Golden Retriever (ratio: 0.4, P = .02), Dachshund (ratio: 0.3, P = .02), Yorkshire Terrier (ratio: 0.18, P = <.001), German Shorthair Pointer (ratio: 0.2, P = .04), American Bulldog (ratio: 0.1, P = .001), Chihuahua (ratio: 0.1, P = .01), Beagle (ratio: 0.1, P < .001), and Standard Poodle (ratio: 0.1, P = .003).…”

Antibody response over time correlated with treatment outcome in 30 dogs naturally infected with Brucella canis (2017–2022)

“…18,19 Delayed diagnosis of discospondylitis can be detrimental to the prognosis, as both the vertebral lesion and neurological status can worsen with time. 18 Changes consistent with infection can be detected at earlier stages when using magnetic resonance imaging or computed tomography, compared with radiography [20][21][22] ; however, these imaging modalities can be cost prohibitive. Often the progression of disease at the time of presentation is substantial, warranting pain management.…”