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The conformation of spinal arachnoid diverticula (SAD) and their clinical implications are poorly characterized in dogs. This retrospective cross‐sectional study describes different SAD conformations in dogs and aims to identify if there is an association between SAD conformation and clinical features, localization, syringomyelia (SM) presence, concurrent vertebral condition, treatment option, and short as well as long‐term outcome. Sixty‐two dogs were included (12 cervical and 50 thoracolumbar SAD). All dogs with a cervical SAD had a cranial tethered conformation and were not included in the statistical analysis. Half of the dogs with a thoracolumbar SAD were cranial tethered, and the other half were caudal tethered. SM associated with SAD had a moderate prevalence in the cervical region (58.3%) and a high prevalence in the thoracolumbar region (82%). All dogs with the presence of SM and caudal tethered SAD had a cranial positioned SM, and all dogs with SM and a cranial tethered SAD had a caudal positioned SM. The SM absolute length and SM length/L2 ratio were significantly higher (P =.018, respectively) in the caudal tethered SAD compared with the cranial tethered SAD. The short‐term outcome was statistically different (P =.045) between caudal and cranial tethered thoracolumbar SAD, but not the long‐term outcome (P =.062). Multivariable logistic regression identified thoracolumbar caudal tethered SAD conformation had a better short‐term outcome (P = 0.017, OR: 0.043, CI: 0.003–0.563), independently of SM length measurements. SAD conformation in dogs can influence SM formation. A possible link between short‐term outcome and SAD conformation was found, but further research is warranted. [ABSTRACT FROM AUTHOR]

Background: Intervertebral disc herniation is widely recognized as the most common cause of myelopathy in dogs older than 2 years; however, the prevalence of various causes of myelopathy in younger dogs has not been reported. Hypothesis/Objectives: To describe the prevalence, clinical presentation, and etiology of myelopathy in dogs aged 18 months or less. Secondarily, to investigate which clinical features were associated with each of the most common etiologies. Animals: Two hundred twenty‐four dogs aged 18 months or less with myelopathy were included in the study. Methods: Retrospective review of clinical records from 4 referral institutions. Multivariable logistic regression analyses assessed which clinical features were associated with each diagnosis. Results: French bulldogs (n = 51, 22.8%), pugs (n = 18, 8.0%), crossbreeds (n = 12, 5.4%), and English bulldogs (n = 11, 4.9%) were the most frequently affected breeds. Overall, 31 diagnoses were reached. The 5 most frequent diagnoses were vertebral malformation (VM; n = 42, 18.8%), spinal arachnoid diverticulum (SAD; n = 28, 12.5%), traumatic fracture of the vertebral column (n = 22, 9.8%), atlantoaxial instability (n = 18, 8.0%), and osseous‐associated cervical spondylomyelopathy (n = 17, 7.6%). Intervertebral disc extrusion (IVDE) accounted for 4.5% of cases (n = 10). A final diagnosis of VM was associated with younger, screw‐tailed, and pug breeds with chronic signs of T3‐L3 myelopathy. SAD was associated with screw‐tailed and pug breeds with nonpainful clinical signs. Intervertebral disc extrusion was associated with older, screw‐tailed, and pug breeds with shorter duration of clinical signs. Conclusions and Clinical Importance: Prioritization of differential diagnoses for dogs presenting with signs of myelopathy when aged 18 months or less should differ to those for older dogs, with IVDE not the most common cause in the former. [ABSTRACT FROM AUTHOR]

Background: Meningoencephalitis of unknown origin (MUO) comprises a group of noninfectious inflammatory diseases affecting the central nervous system of dogs. Previous studies have reported individual risk factors for survival but prognostication for MUO remains challenging. Objectives: Identify clinical prognostic variables in dogs with MUO. Animals: A retrospective study of 447 dogs presented to 2 UK referral hospitals and diagnosed with MUO. Methods: Medical records of dogs diagnosed with MUO were retrospectively reviewed. Multivariable logistic regression was used for the identification of risk factors for survival and Cox proportional hazards analysis for the identification of risk factors for clinical relapse. Results: Eighty‐two percent (366/447) of dogs with presumptive MUO survived to discharge and 63.5% (284/447) were alive at 6 months; 36% of the latter (103/284) had persistent neurological deficits. Breed (pugs; P =.03), epileptic seizures (P <.001), paresis (P <.001), and higher neurodisability scale (NDS) score (P <.001) at presentation were negatively associated with survival to 6 months. Dogs with persistent deficits had higher NDS scores on presentation (P =.001). Median follow‐up time was 11 months (interquartile range [IQR], 1‐24) and 50.6% (160/316) relapsed during treatment (median time to relapse, 7 months; IQR, 2‐15). Incomplete resolution of the clinical signs during the 6 months after diagnosis (P <.001), higher NDS score (P <.001), and longer duration of the clinical signs (P <.001) were associated with relapse. Conclusions and Clinical Importance: Knowledge of risk factors associated with survival, incomplete recovery and clinical relapse in MUO can help guide monitoring and treatment and improve owner communications regarding prognosis for this debilitating disease. [ABSTRACT FROM AUTHOR]

Background: Limited information is available regarding intervertebral disc herniation (IVDH) and its treatment in cats. Objectives: Describe outcomes after surgical or conservative treatment of cats with thoracolumbar and lumbosacral IVDH. Animals: Ninety‐two cats from 2 referral populations (2012‐2022) with compressive IVDH between the T3 and S1 vertebrae. Methods: Retrospective cohort study evaluating outcomes of surgical (49 cats) and conservative (36 cats) management of IVDH; 7 cats were euthanized at diagnosis. Outcome was assessed using hospital and referring veterinarian records and client questionnaires. Successful outcome was defined as regained or improved ambulation, urinary and fecal continence, and no requirement for analgesic medication. Results: Incidence of IVDH during the study period was 0.44% (92/20849). Surgical treatment resulted in 62% (6 weeks) and 74% success (6 months). Conservative treatment resulted in 54% (6 weeks) and 65% success (6 months). Neurological grade at presentation was higher in cats treated surgically (median, 2; range, 1‐5) than in those treated conservatively (median, 2; range, 0‐4; P =.001). Regardless of treatment type, cats suffering trauma were more likely to have a successful outcome 6 weeks after treatment compared with those without history of trauma (odds ratio, 5.3; 95% confidence interval, 1.05‐26.78; P =.04). Neurological deficits remained in the majority of cats for both treatment types (92%, conservative; 86%, surgical at 6 weeks). Acute‐on‐chronic IVDH with characteristics of both extrusion and protrusion were identified in 10% of cats. Conclusions and Clinical Importance: Conservative treatment could be as effective as surgical decompression in cats with thoracolumbar or lumbosacral IVDH. [ABSTRACT FROM AUTHOR]

Background: Although idiopathic episodic head tremor (IEHT) in dogs is well‐known, little is known about structural brain lesions causing structural episodic head tremor (SEHT). Hypothesis/Objectives: Describe semiology, magnetic resonance imaging (MRI) findings and outcome of dogs with IEHT or SEHT. We hypothesized that structural lesions affecting the middle cranial fossa or mesencephalic aqueduct could lead to SEHT. Animals: One hundred dogs with IEHT (n = 71) or SEHT (n = 29). Methods: Retrospective, multicenter, study of dogs with episodic (nonintentional) head tremor and brain MRI between 2004 and 2022. Results: Lesions on MRI in SEHT dogs were localized to the middle cranial fossa (15/29), cerebrocortex (3/29), brainstem (2/29), fourth ventricle (1/29) or multifocal (8/29) with thalamus involvement (6/8). Secondary compression of the mesencephalic aqueduct (19/29), third ventricle or interthalamic adhesion or both (14/29) was common. The most common underlying condition in dogs with SEHT was a pituitary mass. Dogs with SEHT were older, had additional neurological signs and were more likely to be euthanized after diagnosis (P <.001 for all) compared to IEHT dogs. Two SEHT dogs had only tremor. In IEHT dogs, 8/10 owners reported that the tremor decreased or abated over time (range, 106‐2315 days) without treatment. Tremor remission occurred in SEHT dogs treated for underlying meningoencephalitis. Conclusions and Clinical Importance: Presence of additional neurological signs and older age may indicate an underlying structural cause for episodic (nonintentional) head tremor involving the mesencephalic aqueduct, third ventricle, interthalamic adhesion or some combination of these. An intracranial structural abnormality cannot be excluded in dogs with normal neurological examination. [ABSTRACT FROM AUTHOR]

A 4‐year‐old, male, entire Newfoundland was presented for investigation of an acute onset cervical ventroflexion and pyrexia, 4 days following a hip replacement surgery. Neurological examination confirmed prominent cervical ventroflexion characterised by an inability to raise the head, without evidence of cervical hyperaesthesia or associated neurological deficits. Magnetic resonance imaging identified focal, bilaterally symmetrical changes to the semispinalis cervicis musculature, responsible for elevation of the head. The presentation and diagnostic imaging findings appeared analogous to dropped‐head syndrome in humans. Toxoplasma IgG antibodies were found to be mildly elevated, and therefore treatment with clindamycin was initiated. The dog responded well to treatment and was reported to be clinically normal 2 months thereafter. [ABSTRACT FROM AUTHOR]

Background: Limited recent data exists regarding discospondylitis in dogs. Hypothesis/Objectives: (i) Describe the signalment, clinical and imaging findings, etiologic agents, treatment, and outcome of dogs with discospondylitis, (ii) determine diagnostic agreement between radiographs, CT, and MRI with regard to the presence of discospondylitis and its location, and (iii) determine risk factors for relapse and progressive neurological deterioration. Animals: Three hundred eighty‐six dogs. Methods: Multi‐institutional retrospective study. Data extracted from medical records were: signalment, clinical and examination findings, diagnostic results, treatments, complications, and outcome. Potential risk factors were recorded. Breed distribution was compared to a control group. Agreement between imaging modalities was assessed via Cohen's kappa statistic. Other analyses were performed on categorical data, using cross tabulations with chi‐squared and Fisher's exact tests. Results: Male dogs were overrepresented (236/386 dogs). L7‐S1 (97/386 dogs) was the most common site. Staphylococcus species (23/38 positive blood cultures) were prevalent. There was a fair agreement (κ = 0.22) between radiographs and CT, but a poor agreement (κ = 0.05) between radiographs and MRI with regard to evidence of discospondylitis. There was good agreement between imaging modalities regarding location of disease. Trauma was associated with an increased risk of relapse (P =.01, OR: 9.0, 95% CI: 2.2‐37.0). Prior steroid therapy was associated with an increased risk of progressive neurological dysfunction (P =.04, OR: 4.7, 95% CI: 1.2‐18.6). Conclusions and Clinical Importance: Radiograph and MRI results could be discrepant in dogs with discospondylitis. Prior trauma and corticosteroids could be associated with relapse and progressive neurological dysfunction, respectively. [ABSTRACT FROM AUTHOR]

Background: Blood‐brain barrier (BBB) permeability can be assessed quantitatively using advanced imaging analysis. Hypothesis/Objectives: Quantification and characterization of blood‐brain barrier dysfunction (BBBD) patterns in dogs with brain tumors can provide useful information about tumor biology and assist in distinguishing between gliomas and meningiomas. Animals: Seventy‐eight hospitalized dogs with brain tumors and 12 control dogs without brain tumors. Methods: In a 2‐arm study, images from a prospective dynamic contrast‐enhanced (DCE; n = 15) and a retrospective archived magnetic resonance imaging study (n = 63) were analyzed by DCE and subtraction enhancement analysis (SEA) to quantify BBB permeability in affected dogs relative to control dogs (n = 6 in each arm). For the SEA method, 2 ranges of postcontrast intensity differences, that is, high (HR) and low (LR), were evaluated as possible representations of 2 classes of BBB leakage. BBB score was calculated for each dog and was associated with clinical characteristics and tumor location and class. Permeability maps were generated, using the slope values (DCE) or intensity difference (SEA) of each voxel, and analyzed. Results: Distinctive patterns and distributions of BBBD were identified for intra‐ and extra‐axial tumors. At a cutoff of 0.1, LR/HR BBB score ratio yielded a sensitivity of 80% and specificity of 100% in differentiating gliomas from meningiomas. Conclusions and Clinical Importance: Blood‐brain barrier dysfunction quantification using advanced imaging analyses has the potential to be used for assessment of brain tumor characteristics and behavior and, particularly, to help differentiating gliomas from meningiomas. [ABSTRACT FROM AUTHOR]

Background: As they have been seldomly described in the veterinary literature, the aims of this retrospective study were to describe the clinical presentation, MRI findings and long‐term outcome after medical or surgical treatment of dogs presenting with foraminal and far lateral thoracolumbar intervertebral disc herniations. Methods: Retrospective multicentre study of dogs diagnosed with foraminal and far lateral thoracolumbar intervertebral disc herniations between 2009 and 2020 in seven referral hospitals. Results: Thirty‐seven dogs were included. Dachshunds and mixed breeds were most affected. Median age at presentation and duration of clinical signs were 6 years and 14 days, respectively. Pain was the most frequent clinical finding (92%), particularly on spinal palpation and/or hip manipulation, followed by pelvic limb lameness (71%). Eighty‐seven percent of herniations occurred at L5‐L6 or L6‐L7. A good to excellent outcome was seen in 95% of surgically and 90% of medically treated dogs. Conclusion: Although much less frequently recognised than herniation affecting the vertebral canal, foraminal and far lateral thoracolumbar intervertebral disc herniations should be considered in the differential diagnosis list of chondrodystrophic dogs presenting with pain and pelvic limb lameness. Most dogs had a good to excellent outcome following medical or surgical treatment. [ABSTRACT FROM AUTHOR]

The authors have observed a vertebral anomaly in French and English Bulldogs and termed this anomaly "vertebral vascular canal dysplasia (VVCD)." No previously published descriptions of this anomaly were found. The aims of this retrospective, multi‐institutional, observational study were to (1) describe the clinical, CT, and MRI characteristics of VVCD, and (2) estimate the prevalence and describe the characteristics of VVCD in a group of French and English Bulldogs. For descriptions of the anomaly, medical records and imaging studies of nine clinical cases with VVCD from several countries were reviewed. For estimation of prevalence, imaging studies of French and English Bulldogs from the United Kingdom (UK) and Italy were reviewed. All clinical case dogs had ≥5 thoracic vertebrae with VVCD affecting >50% of vertebral body height (VBH). The prevalence of VVCD involving ≥1 thoracic vertebra in the UK population (CT identified) of English Bulldogs and French Bulldogs was, respectively, 83.3% (30/36) and 68.3% (28/41). English Bulldogs had significantly more thoracic vertebrae with VVCD than French Bulldogs (P = < 0.01). The prevalence of VVCD in ≥1 thoracic vertebra in the Italian population (MRI identified) of English Bulldogs and French Bulldogs was, respectively, 21.7% (5/23) and 6.6% (7/106). Vertebral vascular canal dysplasia was observed in normal as well as in malformed vertebrae (e.g., hemivertebrae). Findings from the current study introduced descriptions of VVCD that can be used as background for future studies. [ABSTRACT FROM AUTHOR]

Background: This study aimed to compare the clinical presentation, short and long term outcomes of dogs treated surgically or medically for Osseous associated cervical spondylomyelopathy. Methods: Information collected retrospectively from medical records included signalment, neurological status and treatment type. Surgical treatment consisted of dorsal laminectomy. Medical treatment involved restricted exercise and medication. Improvement or deterioration in neurological status was determined at discharge, re‐examination 4–8 weeks post‐treatment and by telephone interview with the referring veterinary surgeon or owner at the time of the study, which ranged from 8–54 months following the discharge (median, 16 months). Results: Twenty‐four dogs were treated surgically and 30 medically. Neurological grade at clinical presentation was significantly higher in surgically treated dogs (p = 0.004). Transient early postoperative neurological deterioration occurred in 73.1% of surgically treated dogs. For medical cases, long term improvement was seen in 15% of cases, remained static in 40% and deterioration in 45%. Surgical treatment resulted in long term improvement in 67% of cases, remained static in 29% and deterioration in 4% of cases. Conclusion: This study suggests that surgery is a favourable treatment option, however, requires intensive post‐operative care. Medical treatment was associated with a guarded prognosis but could be a viable treatment option for selected dogs. [ABSTRACT FROM AUTHOR]

Hemangiosarcoma is the most common metastatic tumor involving the brain in dogs but detailed published descriptions of the magnetic resonance imaging (MRI) features are lacking. The objective of this multi‐center, retrospective case series study was to describe MRI characteristics of canine hemangiosarcoma affecting the central nervous system (CNS). Medical records of seven referral institutions were retrospectively reviewed. Dogs were included if they had a histopathologically confirmed diagnosis of hemangiosarcoma affecting the CNS and undergone an MRI of the brain and/or vertebral column. Lesions were independently evaluated by two observers. Twenty dogs met the inclusion criteria and one dog had both intracranial and intramedullary hemangiosarcoma. Consistent MRI features included heterogeneous (17/21) lesions in all sequences with mainly mixed signal intensity (12/21), presence of susceptibility artifact on T2*w (15/16), associated moderate to severe perilesional edema (21/21), and moderate to strong (20/21) heterogeneous (14/21) or ring‐like (6/21) contrast enhancement. Intracranial hemangiosarcoma was frequently multiple and intra‐axial, affecting consistently the telencephalon and no differences in MRI features were found between primary and metastatic hemangiosarcoma. This is the first MRI description of primary intracranial hemangiosarcoma and primary intracranial epithelioid hemangiosarcoma. Vertebral hemangiosarcomas were segmental poorly marginated polyostotic and highly aggressive lesions invading the thoracic vertebral canal and paraspinal tissues. Epidural hemangiosarcomas were single and well‐marginated lesions in the thoracolumbar and/or lumbar region. Intramedullary hemangiosarcomas were cervical, metastatic in origin, and frequently (3/4) accompanied by intracranial lesions. These described MRI features will aid early identification of hemangiosarcoma guiding subsequent diagnostics and therapeutics. [ABSTRACT FROM AUTHOR]

An English Springer Spaniel presented with an acute onset, progressive, left pelvic limb lameness. Magnetic resonance imaging, computed tomography and intraoperative findings revealed an enlarged L5 left nerve root without additional abnormalities and, therefore, no underlying cause for the nerve root enlargement could be identified. The dog made a quick recovery following hemilaminectomy and was clinically normal 45 months after surgery. Morphometric analysis was obtained by measuring sagittal intervertebral foramen (IVF) surface areas. IVF areas in the clinical case were similar to unpublished data in normal English Springer Spaniels. Although a diagnosis of primary IVF stenosis could not be confirmed morphometrically, the lack of additional anatomical abnormalities in combination with an excellent clinical outcome was supportive of this condition. Nerve root enlargement can be caused by benign or malignant conditions. [ABSTRACT FROM AUTHOR]

An approximately 1‐year‐old female entire crossbreed dog presented for further assessment of a traumatically induced T3‐L3 myelopathy. CT demonstrated multiple vertebral fractures, a large paravertebral abscess with intracanal extension and an abdominal wall rupture. Given the active infection surrounding the lumbar fracture site, permanent internal fixation devices were deemed less favourable. An external skeletal fixator construct was placed using percutaneously placed positive profile pins and Steinmann pins as connecting bars. Repeat CT 8 weeks following surgery revealed good realignment of the vertebral column and resolution of the sublumbar abscess. The external fixator was removed and gradual return to exercise instructed over the following 8 weeks. This case report describes the use of an external vertebral skeletal fixator in a young dog with traumatic vertebral fracture when traditional methods were considered less favourable. [ABSTRACT FROM AUTHOR]

Background: Although, vestibular syndrome is a common neurological presentation, little is known about the diagnostic value of cerebrospinal fluid (CSF) analysis in vestibular syndrome in dogs. Methods: Medical records were retrospectively reviewed, and dogs with vestibular disease that had undergone magnetic resonance imaging of the head, CSF analysis and were diagnosed with central or peripheral vestibular syndrome were included. Disorders affecting the central vestibular system included meningoencephalitis of unknown origin (MUO), brain neoplasia, ischaemic infarct, intracranial empyema or metronidazole toxicity. Disorders affecting the peripheral vestibular system included idiopathic vestibular disease, otitis media/interna or neoplasia affecting the inner ear structures. Total nucleated cell concentration (TNCC), total protein concentration (TP) and cytologic assessment were recorded. Results: A total of 102 dogs met the inclusion criteria. The sensitivity and specificity of increased CSF TNCC to differentiate central from peripheral vestibular syndrome was 49% and 90%, while the sensitivity and specificity of increased TP was 58% and 39%, respectively. The TNCC and TP in dogs with MUO were significantly higher than in dogs with idiopathic vestibular disease (p = 0.000 and p = 0.004). MUO was associated with lymphocytic pleocytosis, while idiopathic vestibular disease and ischaemic infarct were associated with the presence of activated macrophages or normal cytology (p = 0.000). Conclusion: Although consistent CSF abnormalities were observed in dogs with MUO, CSF analysis did not allow reliable differentiation between central and peripheral vestibular syndrome. CSF analysis is not reliable as the sole diagnostic technique in dogs with vestibular disease. [ABSTRACT FROM AUTHOR]

Acquired cervical scoliosis previously has been reported in dogs as a clinical sign associated with Chiari‐like malformation and syringomyelia but has not been described with inflammatory central nervous system disease. A 9‐month‐old Flat‐Coated Retriever was presented with an acute onset of cervical scoliosis with no other neurological deficits. Magnetic resonance imaging identified a focal, poorly defined intramedullary lesion within the cranial cervical spinal cord. Cerebrospinal fluid (CSF) analysis indicated mononuclear pleocytosis consistent with a diagnosis of meningomyelitis of unknown etiology. A second dog, a 3‐year‐old female spayed German Shepherd, developed an acute onset of cervical scoliosis with mild generalized proprioceptive ataxia 2 months after commencing immunosuppressive corticosteroid treatment for presumed steroid‐responsive meningitis‐arteritis. Magnetic resonance imaging at the time of diagnosis disclosed a similar intramedullary lesion within the cranial cervical spinal cord, with a neutrophilic pleocytosis on CSF analysis. Both dogs were treated with immunosuppressive dosages of prednisolone, along with cytosine arabinoside in the first dog, with resolution of cervical scoliosis seen in both. To our knowledge, this is the first report of acute onset acquired, reversible cervical scoliosis in dogs with presumed immune‐mediated meningomyelitis. [ABSTRACT FROM AUTHOR]

Congenital cervical vertebral malformations (CCVM) have been infrequently reported in veterinary medicine, with limited examples of axis spinous process malformations. The objective of this retrospective cross‐sectional study was to describe the radiological characteristics, prevalence, and clinical relevance of a characteristic axis vertebral malformation in a sample of English Bull Terriers (EBTs). Medical records and diagnostic imaging studies of the cervical vertebral column of EBTs presenting for any reason were reviewed and described. Based on evaluation of the images, EBTs were divided in two groups; axis spinous process malformation and normal cases. Referring veterinary surgeons were contacted for long‐term follow‐up information. A total of 27 cervical radiographs, 23 CT, and nine MRI studies from 53 EBTs were reviewed. An axis spinous process malformation, characterized by a linear defect of varying length along the base of the spinous process, was identified in 22 of 53 EBTs (41.5%). There was no significant difference in age, body weight, or sex (P <.05) between EBTs with and without the malformation. No traumatic causes or clinical signs were identified in EBTs with the malformation that could be directly attributed to it. To the authors' knowledge, this is the first report of a malformation of the axis spinous process in a sample of EBTs. The malformation was not associated with clinical signs and should not be misinterpreted as a traumatic vertebral fracture or other pathology. [ABSTRACT FROM AUTHOR]

Background: Although the use of clinical reasoning has been evaluated for several neurological presentations, this approach has not yet been investigated for dogs with vestibular syndrome. Methods: Two hundred and thirty‐nine dogs presenting with vestibular syndrome were included in this retrospective study. Univariate analysis of variables (clinical history, signalment, clinical presentation and neurological examination findings) was performed. Variables with p < 0.3 were selected for logistic regression. Results: Ninety‐five percent of dogs were represented by eight conditions: idiopathic vestibular disease (n = 78 dogs), otitis media interna (n = 54), meningoencephalitis of unknown origin (n = 35), brain neoplasia (n = 26), ischaemic infarct (n = 25), intracranial empyema (n = 4), metronidazole toxicity (n = 3) and neoplasia affecting the middle ear (n = 3). Idiopathic vestibular disease was associated with higher age, higher bodyweight, improving clinical signs, pathological nystagmus, facial nerve paresis, absence of Horner's syndrome and a peripheral localisation. Otitis media interna was associated with younger age, male gender, Horner's syndrome, a peripheral localisation and a history of otitis externa. Ischaemic infarct was associated with older age, peracute onset of signs, absence of strabismus and a central localisation. Conclusions: Discrete clinical features can be used to identify the most likely diagnosis in dogs with vestibular syndrome. [ABSTRACT FROM AUTHOR]

Background: Traumatic skull fractures (TSF) are relatively frequent in dogs and cats, but little information is available regarding their clinical and imaging features. Hypothesis/Objectives: To describe the neurological and computed tomographic (CT) features of a large cohort of dogs and cats with TSF. Animals Ninety‐one dogs and 95 cats with TSF identified on CT. Methods: Multicenter retrospective comparative study. Signalment, cause of trauma, fracture locations and characteristics, presence of neurological deficits, and 1‐week survival were recorded. Fractures were classified according to the extent of fragmentation and displacement. Results: The cranial vault was affected more frequently in dogs (P =.003), whereas the face and base of the cranium more often was affected in cats (P <.001). Cats presented with multiple fractures more frequently (P <.001). All animals with TSF in the cranial vault were more likely to develop neurological signs (P =.02), especially when depressed fractures were present (95% confidence interval [CI], 1.7‐8.2; P =.001). Animals with TSF located only in the facial region were less likely to have neurological signs (odds ratio with Mantel‐Haenszel's method [ORMH], 0.2; 95% CI, 0.1‐0.6; P =.004). Most affected animals (84.9%) survived the first week post‐trauma. Death was more likely with fractures of the cranial vault (P =.003), especially when fragmented (P =.007) and displaced (P =.004). Conclusions and Clinical Importance: Traumatic skull fracture distribution and patterns are different between dogs and cats. Cranial vault fractures were associated with neurological deficits and worse survival. The presence of TSF alone should not be considered a negative prognostic factor because most affected animals survived the first week. [ABSTRACT FROM AUTHOR]

Background: Although thoracic hemivertebra can cause neurological signs, they occur commonly in neurologically normal dogs. Objectives: To evaluate whether computed tomography (CT) findings and factors associated with signalment can be used to differentiate between dogs with and without neurological signs associated with hemivertebra. Animals: One hundred sixty dogs with ≥1 hemivertebrae were retrospectively studied. This group consisted of 40 dogs with clinical signs caused by hemivertebra and 40 French Bulldogs, 40 Pugs, and 40 English Bulldogs that underwent CT for reasons unrelated to neurological disease. Methods: All dogs underwent CT and affected dogs also underwent magnetic resonance imaging. All CT studies were randomly evaluated by an observer blinded to signalment and clinical status. The following variables were evaluated: presence, number, location, and subtype of hemivertebra; presence of vertebral subluxation; severity of vertebral canal stenosis; presence, location, and severity of kyphosis, and number of vertebrae involved in the kyphotic segment. Statistical modeling was performed to identify factors associated with clinical status. Results: Pug breed (odds ration [OR], 10.8; P =.01), more severe kyphosis (OR, 1.1 per grade increase; P < .001), fewer instead of more observed hemivertebrae (OR, 0.8; P = 0.03), and ventrolateral hypoplasia hemivertebra subtype (OR, 4.0; P =.011) were associated with higher likelihood of neurological disease. A Cobb angle of 34.5 degrees corresponded with the highest combined sensitivity and specificity to differentiate between clinically affected and unaffected dogs. Conclusions and Clinical Importance: The variables identified could aid in differentiating between clinically relevant and irrelevant hemivertebra in small breed brachycephalic dogs. [ABSTRACT FROM AUTHOR]

Objective: To describe the clinical presentation, advanced imaging findings, and short‐ and long‐term outcomes in dogs with intracranial empyema. Design: Retrospective case series. Animals: Client‐owned dogs diagnosed with intracranial empyema. Methods: Medical records from 2 referral hospitals were searched for dogs diagnosed with intracranial empyema. To be included in this study, dogs had to fulfill 1 or more of the following 3 inclusion criteria: a magnetic resonance imaging (MRI) scan with space occupying accumulation of extra‐axial material suggestive of empyema, a cerebrospinal fluid analysis suggestive of empyema, or direct visualization of purulent material during intracranial surgery. Results: Nine dogs with intracranial empyema were included, with a median age of 3.5 years (range: 4 mo–12.5 y). All presented as emergencies with 7 of the 9 dogs showing neurological abnormalities and 2 of the 9 with retrobulbar swelling and exophthalmos. Six had surgical intervention, 1 was medically managed, and the remaining 2 dogs were euthanized. Typical MRI findings included extra‐axial, T1‐weighted hypo‐ to isointense, T2‐weighted hyperintense material compared to gray matter with varying degrees of contrast enhancement, with 6 of 8 showing evidence of contiguous infection from adjacent structures on MRI. For 7 dogs, ≥1 samples were sent for culture and sensitivity, with Enterococcus (surgical swab), Streptococcus pneumonia (from cerebral spinal fluid), and coagulase positive Staphylococcus (ear swab) being cultured. The median antimicrobial course length was 6 weeks (range: 2–28 wk). All dogs for which treatment was attempted survived to discharge, with a median hospitalization time of 7 days (range: 4–10 d). Four of the 7 are still alive at the time of writing (1 lost to follow‐up; 2 euthanized for other reasons) with all 4 considered neurologically normal with a successful long‐term outcome. Conclusion: Although intracranial empyema in dogs is a rare condition, excellent outcomes are possible in those cases treated appropriately. [ABSTRACT FROM AUTHOR]

Background: Little is known about the spectrum of underlying disorders in dogs with unilateral masticatory muscle (MM) atrophy. Objectives: To evaluate the clinical presentation, magnetic resonance imaging (MRI) findings, and outcome of dogs with unilateral MM atrophy. Animals: Sixty‐three client‐owned dogs. Methods: The medical database was retrospectively reviewed for dogs that underwent MRI for evaluation of unilateral MM atrophy. Imaging studies were reviewed and follow‐up information was obtained from telephone interviews. Results: Presumptive trigeminal nerve sheath tumor (pTNST) was diagnosed in 30 dogs (47.6%); survival time varied from 1 day to 21 months (median, 5 months). Other extra‐axial mass lesions were observed in 13 dogs (20.6%); survival time varied from 6 days to 25 months (median, 2.5 months). In 18 dogs (28.6%), no abnormalities were observed on MRI; neurological signs only progressed in 1 dog. Diagnosis had a significant influence on the type of neurological abnormalities, with additional neurological deficits observed in most dogs with pTNST and in all dogs with other extra‐axial mass lesions. Diagnosis had a significant effect on euthanasia at the time of diagnosis and likelihood of neurological deterioration. Dogs with mass lesions were more likely to be euthanized or experience neurological deterioration, whereas these outcomes occurred less often in dogs in which no causative lesion could be identified. Conclusions and Clinical Importance: Trigeminal nerve sheath tumors should not be considered the only cause of unilateral MM atrophy. Our results illustrate the importance of performing a neurological examination and MRI when evaluating dogs with unilateral MM atrophy. [ABSTRACT FROM AUTHOR]

Abstract: The aims of this study were to evaluate the prevalence and anatomical characteristics of thoracic caudal articular process dysplasia in French bulldogs, English bulldogs and Pugs presenting for problems unrelated to spinal disease. In this retrospective cross‐sectional study, computed tomography scans of the thoracic vertebral column of these three breeds were reviewed for the presence and location of caudal articular process hypoplasia and aplasia, and compared between breeds. A total of 271 dogs met the inclusion criteria: 108 French bulldogs, 63 English bulldogs, and 100 Pugs. A total of 70.4% of French bulldogs, 84.1% of English bulldogs, and 97.0% of Pugs showed evidence of caudal articular process dysplasia. Compared to French and English bulldogs, Pugs showed a significantly higher prevalence of caudal articular process aplasia, but also a lower prevalence of caudal articular process hypoplasia, a higher number of affected vertebrae per dog and demonstrated a generalized and bilateral spatial pattern more frequently. Furthermore, Pugs showed a significantly different anatomical distribution of caudal articular process dysplasia along the vertebral column, with a high prevalence of caudal articular process aplasia between T10 and T13. This area was almost completely spared in French and English bulldogs. As previously suggested, caudal articular process dysplasia is a common finding in neurologically normal Pugs but this also seems to apply to French and English bulldogs. The predisposition of clinically relevant caudal articular process dysplasia in Pugs is possibly not only caused by the higher prevalence of caudal articular process dysplasia, but also by breed specific anatomical characteristics. [ABSTRACT FROM AUTHOR]

Background Hypothesis/Objectives Animals Methods Results Conclusions and Clinical Importance Limited current information exists regarding discospondylitis within breeds commonly affected by congenital vertebral body malformations.Report the prevalence of discospondylitis in English and French bulldogs and investigate for possible associations of discospondylitis with congenital vertebral body malformations.108 client‐owned dogs.Retrospective multi‐institutional study between June 2010 and 2020. Cases with a diagnosis of discospondylitis on computed tomography (CT) or magnetic resonance imaging (MRI) and complete medical records included. Signalment, discospondylitis location, presence of congenital vertebral body malformations, and the site of maximal kyphosis were recorded.The prevalence of discospondylitis was 3.4 (1.6‐6.7, 95% confidence interval [CI]) times higher in French bulldogs (P < .001) and 4.3 (1.7‐9.8, 95% CI) times higher in English bulldogs (<.001), compared with the overall hospital cohort. One or more vertebral malformations were present in 12 French bulldogs (92.3%), 6 English bulldogs (75.0%), and 1 “other” breed dog (1.1%). Discospondylitis was diagnosed adjacent to congenital vertebral body malformations in 12 (80%) intervertebral discs in French bulldogs and 5 (50%) intervertebral discs in English bulldogs. The median age at presentation was significantly younger in French bulldogs (1.1 years; range, 0.5‐9.2 years) and English bulldogs (1.0 years; range, 0.4‐7.0 years), compared with “other” breed dogs (7.3 years; range, 0.3‐14.0 years; both P < .001).Congenital vertebral body malformations were frequently associated with discospondylitis in French and English bulldogs, with clinical signs commonly encountered at a significantly younger age. [ABSTRACT FROM AUTHOR]