Description and clinical relevance of the variable conformation of canine spinal arachnoid diverticula.

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.

Vertebral and spinal malformations in small brachycephalic dog breeds: Current knowledge and remaining questions.

Small brachycephalic dog breeds, such as the French bulldog, English bulldog and pug have become increasingly popular. These breeds are predisposed to a variety of vertebral and spinal malformations, including hemivertebra, caudal articular process dysplasia, transitional vertebra, cranial thoracic vertebral canal stenosis, spinal arachnoid diverticulum and meningeal fibrosis. Recent studies have provided new insights into the prevalence, anatomical characteristics, pathophysiology and treatment of these conditions. Thoracic hemivertebra, caudal articular process dysplasia, transitional vertebra, and cranial thoracic vertebral canal stenosis occur commonly in neurologically normal dogs. Although the clinical relevance of these vertebral anomalies has therefore been questioned, severe kyphosis and hemivertebra in pugs have been associated with an increased likelihood of neurological signs. Meningeal fibrosis is characterised by the formation of dense intradural fibrotic adhesions, constricting the spinal cord. This condition has been heavily associated with the pug breed. It is in pugs further common to observe multiple concurrent spinal disorder in association with chronic progressive pelvic limb gait abnormalities. This clinical presentation has been referred to as 'pug dog thoracolumbar myelopathy' and potential genetic risk factors have recently been identified. Despite our increased knowledge, many questions remain currently unanswered. This review discusses our current understanding and controversies surrounding vertebral and spinal malformations in small brachycephalic dog breeds.

Once-a-day oral treatment with phenobarbital in cats with presumptive idiopathic epilepsy.

OBJECTIVES: Phenobarbital (PB) q12h is the most common treatment recommendation for cats with recurrent epileptic seizures. Medicating cats may be challenging and result in decreased quality of life for both cat and owner. The aim of this retrospective study was to evaluate treatment with oral PB q24h in cats with presumptive idiopathic epilepsy. METHODS: Nine cats with presumptive idiopathic epilepsy, receiving oral PB q24h, were included in a retrospective descriptive study. RESULTS: Seizure remission was achieved in 88% (8/9) of the cats and good seizure control in 12% (1/9) of the cats, treated with a mean dose of oral PB of 2.6 mg/kg q24h (range 1.4-3.8 mg/kg). No cats required an increase of their PB frequency at any time during a mean follow-up period of 3.5 years (range 1.1-8.0 years). No cats displayed side effects or issues with compliance at the last recorded follow-up. CONCLUSIONS AND RELEVANCE: Once-a-day administration of PB for feline epilepsy was safe and resulted in satisfactory seizure control for the nine cats included in this study. The results of this study justify exploring this topic further in larger prospective studies.

MRI and clinical findings in 133 dogs with recurrent deficits following intervertebral disc extrusion surgery.

BACKGROUND: Recurrence of neurological signs following surgery for intervertebral disc herniation (IVDH) is reported, yet many cases lack MRI-confirmed diagnosis. This study describes the MRI and clinical findings in dogs presenting with recurrence of neurological signs following surgical treatment of IVDH. METHODS: Medical records of dogs that underwent decompressive surgery for IVDH followed by a subsequent MRI within 12 months were retrospectively reviewed. RESULTS: One hundred and thirty-three dogs were identified, all of which initially presented with intervertebral disc extrusion (IVDE). Of these, 109 (81.9%) had a recurrent IVDE, and 24 (18.1%) had an alternative diagnosis that included haemorrhage (n = 10), infection (n = 4), soft tissue encroachment (n = 3), myelomalacia (n = 3) or other (n = 4). Same-site IVDE recurrence or alternative diagnoses were significantly more likely to present within 10 days postoperatively. Thirty-nine percent of dogs presenting with 'early recurrence' had an alternative diagnosis. Type of surgery, fenestration, neurological grade or IVDE site was not significantly associated with the subsequent MRI diagnosis. LIMITATIONS: Limitations include the retrospective study design, the exclusion of conservatively managed recurrences, the variable length of follow-up and differences in the clinicians' surgical experience. CONCLUSION: The most common cause for the recurrence of neurological signs following decompressive spinal surgery was IVDE. Just over one-third of dogs presenting with early recurrence had an alternative diagnosis.

Determining the prevalence and risk factors for positive bacterial culture in canine discospondylitis: 120 cases.

BACKGROUND: Identification of the aetiologic agent in canine discospondylitis is infrequent; and risk factors for a positive bacterial culture have not previously been reported. METHODS: Medical records at three institutions were searched to identify clinical features of dogs with discospondylitis diagnosed via radiography or cross-sectional imaging. Inclusion in this retrospective case-control study required culture of one or more samples. Multivariable binary logistic regression identified features associated with a positive culture. RESULTS: Fifty (42%) of 120 dogs had one or more positive culture results obtained from either urine (28/115), blood (25/78), intervertebral disc aspiration (10/34) or cerebrospinal fluid (1/18). A positive culture was associated with higher bodyweight (p = 0.002, odds ratio [OR] = 1.054, 95% confidence interval [CI]: 1.019-1.089), more sample types cultured (p = 0.037, OR = 1.806, 95% CI: 1.037-3.147) and institution (p = 0.021). The presence of possibly associated preceding events (e.g., surgery), pyrexia, number of disc sites affected and serum C-reactive protein result, among other features, were not statistically significant. LIMITATIONS: All isolates cultured were included since differentiation of true aetiologic agents from contaminants was not possible without histological confirmation and culture from surgical or postmortem biopsies. CONCLUSIONS: Clinical features typically associated with infection were not identified as risk factors for positive culture in canine discospondylitis. The statistical significance of the institution suggests that standardisation of sampling protocols is necessary.

Quantitative analysis of magnetic resonance images for characterization of blood-brain barrier dysfunction in dogs with brain tumors.

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.

Otitis media and interna with or without polyps in cats: association between meningeal enhancement on postcontrast MRI, cerebrospinal fluid abnormalities, and clinician treatment choice and outcome.

OBJECTIVES: The aim of this study was to evaluate the association between meningeal enhancement (MgE) and cerebrospinal fluid (CSF) analysis results, their individual association with bacteriology results from affected ear samples and whether these test results influenced clinicians' therapeutic choice in cats with otitis media and interna (OMI). METHODS: This was a multicentre retrospective study carried out over an 8-year period. Cats diagnosed with OMI, with or without a nasopharyngeal polyp, leading to peripheral vestibular signs were included. Only cats for which MRI with postcontrast T1-weighted sequences and CSF analyses available were included. Cats with intra-axial MRI lesions or empyema were excluded. RESULTS: Fifty-eight cats met the inclusion criteria. MgE was reported in 26/58 cases, of which nine had an abnormal CSF result (increased total nucleated cell count [TNCC] or total protein); 32/58 cases had no MgE, of which 10 showed abnormal CSF results. There was no association between bacteriology results (external ear canal or bulla) and MgE or abnormal CSF results. CSF abnormalities were statistically significantly more common in acute cases (n = 16/37) than in chronic cases (n = 3/21; Fischer's test P = 0.04). Prednisolone was prescribed in 10/16 cases with increased TNCC. Among the 42 cases with normal TNCC, 15 received prednisolone and 13 received non-steroidal anti-inflammatory drugs. Various antimicrobial drugs were prescribed in 53/58 cats. Duration of antimicrobial treatment was similar, regardless of positive bacterial culture (5.58 vs 4.22 weeks), abnormal CSF (5.83 vs 4.76 weeks) or MgE (5.33 vs 4.90 weeks). CONCLUSIONS AND RELEVANCE: No association was found between the CSF and MgE results. Furthermore, no association was found between MgE, CSF or bacteriology findings. In addition, abnormal CSF results might lead the clinician to treat with corticosteroids, but they did not have any impact on duration of antimicrobial treatment. CSF abnormalities were seen significantly less frequently in chronic cases. The outcome tended to be poorer when MgE was detected on MRI.

Clinical presentation, diagnostic findings and outcome of dogs undergoing surgical resection for intracranial meningioma: 101 dogs.

BACKGROUND: Meningioma is the most common primary brain neoplasm in dogs. Further information is required regarding the expected long-term prognosis of dogs following the surgical resection of an intracranial meningioma together with the influence of adjunctive therapies. Whilst there have been several studies reporting the long-term outcome of intracranial meningioma resection following surgery alone, surgery with the use of an ultrasonic aspirator, surgery combined with radiotherapy and surgery combined with the addition of hydroxyurea, it is currently unclear which type of adjunctive therapy is associated with the most favourable outcomes. The objective of this study is to describe the presentation and outcome of dogs undergoing surgery for the resection of an intracranial meningioma and the effect of clinical factors, adjunctive therapies and meningioma histopathological subtype on the long-term outcome. RESULTS: A hundred and one dogs that had intracranial surgery for meningioma resection were investigated from four referral centres. 94% of dogs survived to hospital discharge with a median survival time of 386 days. Approximately 50% of dogs survived for less than a year, 25% survived between 1 and 2 years, 15% survived between 2 and 3 years and 10% survived for greater than 3 years following discharge from hospital. One or more adjunctive therapies were used in 75 dogs and the analysis of the data did not reveal a clear benefit of a specific type of adjunctive therapy. Those dogs that had a transfrontal approach had a significantly reduced survival time (MST 184 days) compared to those dogs that had a rostrotentorial approach (MST 646 days; p < 0.05). There was no association between meningioma subtype and survival time. CONCLUSIONS: This study did not identify a clear benefit of a specific type of adjunctive therapy on the survival time. Dogs that had a transfrontal approach had a significantly reduced survival time. Intracranial surgery for meningioma resection offers an excellent prognosis for survival to discharge from hospital with a median long term survival time of 386 days.

Vertebral vascular canal dysplasia in French and English Bulldogs: Clinical, CT, and MRI characteristics and prevalence.

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.

Sinonasal mycosis following transfrontal craniotomy in three dogs.

CASE DESCRIPTION: Three dogs were presented for investigation of chronic nasal discharge and epistaxis 141, 250, and 357 days after undergoing transfrontal craniotomy to treat an intracranial meningioma (2 dogs) or a meningoencephalocele (1 dog). CLINICAL FINDINGS: CT findings were consistent with destructive rhinitis and frontal sinusitis in all 3 dogs, with results of histologic examination and fungal culture of samples obtained during frontal sinusotomy confirming mycotic infection. Frontal sinusotomy revealed fungal plaques covering a combination of bone and residual surgical tissue adhesive at the site of the previous craniotomy in all 3 dogs. Aspergillus spp were identified in all 3 dogs, and Chrysosporium sp was also identified in 1 dog. TREATMENT AND OUTCOME: Surgical curettage was followed by antifungal treatment (topical clotrimazole in 2 dogs and oral itraconazole for 3 months in 1 dog). Nasal discharge improved in the short-term but recurred in all dogs 99, 118, and 110 days after frontal sinusotomy. One dog received no further treatment, 1 dog received an additional 8.5 months of oral itraconazole treatment, and 1 dog underwent 2 additional surgical debridement procedures. At last follow-up, 2 dogs were alive 311 and 481 days after frontal sinusotomy; the third dog was euthanized because of status epilepticus 223 days after frontal sinusotomy. CLINICAL RELEVANCE: Sinonasal mycosis should be considered as a potential complication in dogs developing persistent mucopurulent nasal discharge, intermittent epistaxis, and intermittent sneezing following transfrontal craniotomy. The pathophysiology may be multifactorial, and potential risk factors, including use of surgical tissue adhesive in the frontal sinus, require further investigation.

MRI features of canine hemangiosarcoma affecting the central nervous system.

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.

Comparing the clinical presentation and outcomes of dogs receiving medical or surgical treatment for osseous-associated cervical spondylomyelopathy.

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.

Using Deep Learning to Detect Spinal Cord Diseases on Thoracolumbar Magnetic Resonance Images of Dogs.

Deep Learning based Convolutional Neural Networks (CNNs) are the state-of-the-art machine learning technique with medical image data. They have the ability to process large amounts of data and learn image features directly from the raw data. Based on their training, these networks are ultimately able to classify unknown data and make predictions. Magnetic resonance imaging (MRI) is the imaging modality of choice for many spinal cord disorders. Proper interpretation requires time and expertise from radiologists, so there is great interest in using artificial intelligence to more quickly interpret and diagnose medical imaging data. In this study, a CNN was trained and tested using thoracolumbar MR images from 500 dogs. T1- and T2-weighted MR images in sagittal and transverse planes were used. The network was trained with unremarkable images as well as with images showing the following spinal cord pathologies: intervertebral disc extrusion (IVDE), intervertebral disc protrusion (IVDP), fibrocartilaginous embolism (FCE)/acute non-compressive nucleus pulposus extrusion (ANNPE), syringomyelia and neoplasia. 2,693 MR images from 375 dogs were used for network training. The network was tested using 7,695 MR images from 125 dogs. The network performed best in detecting IVDPs on sagittal T1-weighted images, with a sensitivity of 100% and specificity of 95.1%. The network also performed very well in detecting IVDEs, especially on sagittal T2-weighted images, with a sensitivity of 90.8% and specificity of 98.98%. The network detected FCEs and ANNPEs with a sensitivity of 62.22% and a specificity of 97.90% on sagittal T2-weighted images and with a sensitivity of 91% and a specificity of 90% on transverse T2-weighted images. In detecting neoplasms and syringomyelia, the CNN did not perform well because of insufficient training data or because the network had problems differentiating different hyperintensities on T2-weighted images and thus made incorrect predictions. This study has shown that it is possible to train a CNN in terms of recognizing and differentiating various spinal cord pathologies on canine MR images. CNNs therefore have great potential to act as a "second eye" for imagers in the future, providing a faster focus on the altered image area and thus increasing workflow in radiology.

Diagnosis, treatment and postsurgical complications in a dog with epileptic seizures and a naso-ethmoidal meningoencephalocele.

BACKGROUND: Naso-ethmoidal meningoencephalocele is usually a congenital anomaly consisting of a protrusion of cerebral tissue and meninges into the ethmoidal labyrinth. The condition is a rare cause of structural epilepsy in dogs. We report the clinical presentation, surgical intervention, postoperative complications and outcome in a dog with drug resistant epilepsy secondary to a meningoencephalocele. CASE PRESENTATION: A 3.3-year-old male neutered Tamaskan Dog was referred for assessment of epileptic seizures secondary to a previously diagnosed left-sided naso-ethmoidal meningoencephalocele. The dog was drug resistant to medical management with phenobarbital, potassium bromide and levetiracetam. Surgical intervention was performed by a transfrontal craniotomy with resection of the meningoencephalocele and closure of the dural defect. Twenty-four hours after surgery the dog demonstrated progressive cervical hyperaesthesia caused by tension pneumocephalus and pneumorrhachis. Replacement of the fascial graft resulted in immediate resolution of the dog's neurological signs. Within 5 months after surgery the dog progressively developed sneezing and haemorrhagic nasal discharge, caused by sinonasal aspergillosis. Systemic medical management with oral itraconazole (7 mg/kg orally q12h) was well-tolerated and resulted in resolution of the clinical signs. The itraconazole was tapered with no relapsing upper airway signs. The dog's frequency of epileptic seizures was not affected by surgical resection of the meningoencephalocele. No treatment adjustments of the anti-epileptic medication have been necessary during the follow-up period of 15 months. CONCLUSIONS: Surgical resection of the meningoencephalocele did not affect the seizure frequency of the dog. Further research on prognostic factors associated with surgical treatment of meningoencephaloceles in dogs is necessary. Careful monitoring for postsurgical complications allows prompt initiation of appropriate treatment.

Cerebrospinal fluid analysis lacks diagnostic specificity in dogs with vestibular disease.

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.

Clinical reasoning in canine vestibular syndrome: Which presenting factors are important?

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.

Clinical reasoning in feline vestibular syndrome: which presenting features are the most important?

OBJECTIVES: The aim of this study was to evaluate whether clinical variables from the history, clinical presentation, and physical and neurological examinations of cats with vestibular syndrome were statistically predictive of the underlying diagnosis. METHODS: In total, 174 cats presenting with vestibular syndrome between January 2010 and May 2019 were investigated. Univariate statistical analysis of clinical variables was performed and those statistically associated with a diagnosis were retained for multivariable binary logistic regression modelling. RESULTS: The seven most prevalent diagnoses represented 95% of vestibular presentations, which included: otitis media/interna (n = 48), idiopathic vestibular syndrome (n = 39), intracranial neoplasia (n = 24), middle ear polyp (n = 17), feline infectious peritonitis (n = 13), thiamine deficiency (n = 13) and intracranial empyema (n = 11). Idiopathic vestibular syndrome was commonly associated with non-purebred cats and had 17.8 times the odds of an improving clinical progression (95% confidence interval [CI] 1.3-250.0; P = 0.03). Intracranial neoplasia was associated with older age and chronic onset of clinical signs, and was significantly more likely to have a central vestibular neuroanatomical localisation (95% CI 8.5-344,349,142.0; P = 0.015) with postural deficits on neurological examination. Thiamine deficiency was more common in female cats, with 52.6 times the odds of a waxing and waning clinical progression (95% CI 1.2-1000; P = 0.038) and 6.8 times the odds of presenting with bilateral vestibular signs (95% CI 1.0-45.7; P = 0.047) and wide excursions of the head (95% CI 1.0-45.7; P = 0.047). Middle ear polyps were associated with 8.8 times the odds of presenting with Horner syndrome (95% CI 1.5-50.0; P = 0.015). CONCLUSIONS AND RELEVANCE: Although it may be difficult to identify the underlying diagnosis in cats with vestibular syndrome from the presenting features alone, there are instances in which discrete clinical features may help to guide clinical reasoning when evaluating cats with vestibular presentations.

Clinical reasoning in canine cervical hyperaesthesia: which presenting features are important?

BACKGROUND: To evaluate whether clinical features from the history, presentation, physical and neurological examination of dogs with cervical hyperaesthesia are statistically predictive of the underlying diagnosis. METHODS: Two hundred and ninety-eight dogs presenting with cervical hyperaesthesia between January 2010 and October 2018 were investigated. Only neurologically normal dogs with cervical hyperaesthesia on examination were included, while those with concurrent neurological deficits including gait abnormalities and proprioceptive deficits were excluded. Univariate analysis of clinical variables was performed, and those associated with each diagnosis were retained for multivariable binary logistic regression models. RESULTS: Ninety-five per cent of cervical hyperaesthesia presentations were represented by eight conditions that included steroid-responsive meningitis arteritis (SRMA; n=100), intervertebral disc extrusion (n=78), syringomyelia (SM; n=51), intervertebral disc protrusion (n=30), neoplasia (n=8), cervical spondylomyelopathy (n=7), immune-mediated polyarthritis (n=5) and meningoencephalomyelitis of unknown aetiology (n=5). Younger age (P=0.003), pyrexia (P=0.003) and haematology abnormalities (P=0.03) comprising leucocytosis, neutrophilia or monocytosis were associated with a diagnosis of SRMA. CONCLUSIONS: Easy-to-recognise clinical features can be used to identify the most likely differential diagnosis in neurologically normal dogs with cervical hyperaesthesia, which may aid the decision making of veterinary surgeons evaluating dogs with this presentation.

Thoracic vertebral canal stenosis in cats: clinical features, diagnostic imaging findings, treatment and outcome.

OBJECTIVES: The aim of this study was to describe the clinical features, diagnostic imaging findings, treatment and outcome in cats with thoracic vertebral canal stenosis (TVCS). METHODS: Medical records and imaging studies of cats with TVCS were retrospectively reviewed. Outcome was acquired from patient records and from owners or referring veterinary surgeons via a telephone questionnaire. For each case, breed-, age- and sex-matched controls were identified with CT imaging of the thoracic vertebral column. For each cat, vertebral canal height was determined at three levels for each thoracic vertebra. Vertebral canal heights were compared between control cats of different breeds and between affected and control cats of the same breed. RESULTS: Nine TVCS cases were included. British Shorthairs and male neutered cats were over-represented (P <0.05). Median age at presentation was 9 years. All cats were presented for a chronic, progressive, painful, ambulatory, T3-L3 myelopathy. Five cats were treated conservatively, three surgically and one was euthanased. Two cats treated surgically demonstrated improvement of clinical signs and one demonstrated initial improvement followed by deterioration. Of the conservatively treated cats, three deteriorated and two improved. Compared with controls, affected cats had a lower vertebral canal height at multiple thoracic vertebral levels, being most prominent for British Shorthairs and domestic shorthairs (P <0.05). Unaffected British Shorthairs had a lower thoracic vertebral canal height at multiple levels than control domestic shorthairs (P <0.05). CONCLUSIONS AND RELEVANCE: TVCS should be considered a differential diagnosis in middle-aged to older cats presenting with a chronic, progressive, painful, T3-L3 myelopathy. The predisposition of British Shorthairs could be explained by a narrower vertebral canal in this breed.

Evaluation of prognostic factors for return of urinary and defecatory function in cats with sacrocaudal luxation.

OBJECTIVES: The aim of this study was to evaluate outcomes and prognostic factors for cats with sacrocaudal luxation. METHODS: Medical records and radiographs were reviewed for cats with sacrocaudal luxation. Information obtained from the clinical records included signalment, clinical presentation, concurrent traumatic injuries, treatment details, outcome and survival time. Severity of neurological signs was graded from 1 to 5, based on previous grading systems for cats with sacrocaudal luxation. Degree of vertebral displacement was calculated on survey radiographs. Outcomes were collected from serial neurological examinations and telephone interviews. Cats had to be given a minimum of 30 days to regain urinary function to be included in the study. RESULTS: Seventy cats were included. Fifty-five of 61 cats (90%) regained voluntary urinary function. A higher neurological grade was associated with a decreased likelihood (P = 0.01) and longer duration (P = 0.0003) of regaining urinary function. No significant associations were found between urinary outcome and age, sex, anal tone, perineal sensation, tail base sensation, degree of craniocaudal or dorsoventral sacrocaudal displacement, concurrent orthopaedic injury, tail amputation, defecatory function at diagnosis and survival. Cats that regained defecatory function had longer survival times than those that did not recover defecatory function (P = 0.03). Defecatory outcome was not significantly associated with any other variables. CONCLUSIONS AND RELEVANCE: In agreement with previous studies, neurological grade is the most important prognostic indicator for cats with sacrocaudal luxation. Determination of the severity of neurological signs can also aid in advising owners the time frame in which urinary function is expected to return. Faecal incontinence may be a more important prognostic factor than previously suspected.