Mechanical quantitative sensory testing in cavalier King Charles spaniels with and without syringomyelia.

BACKGROUND: Syringomyelia (SM) is a debilitating condition in the cavalier King Charles spaniel (CKCS) that results in neuropathic pain and diminished quality of life. Von Frey aesthesiometry (VFA) is a method of mechanical quantitative sensory testing that provides an objective sensory threshold (ST) value and can be used to quantify neuropathic pain (NP) and monitor response to therapy. The utility of VFA has been previously established in client-owned dogs with acute spinal cord injury but the technique has not been evaluated in dogs with SM. The goal of this study was to evaluate ST, as determined by VFA, in dogs with and without SM, to assess the utility of VFA in quantifying NP in SM-affected dogs. We hypothesized the SM-affected CKCS would have lower ST values, consistent with hyperesthesia, when compared to control CKCS. Additionally, we hypothesized that ST values in SM-affected dogs would be inversely correlated with syrinx size on MRI and with owner-derived clinical sign scores. RESULTS: ST values for the thoracic and pelvic limbs differed significantly between the SM-affected and control CKCS (p = 0.027; p = 0.0396 respectively). Median ST value (range) for the thoracic limbs was 184.1 g (120.9-552) for control dogs, and 139.9 g (52.6-250.9) for SM-affected dogs. The median ST value (range) for the pelvic limbs was 164.9 g (100.8-260.3) in control dogs and 129.8 g (57.95-168.4) in SM-affected dogs. The ST values in SM-affected dogs did not correlate with syrinx height on MRI (r = 0.314; p = 0.137). Owner-reported clinical sign scores showed an inverse correlation with pelvic limb ST values, where dogs with lower ST values (hyperesthesia) were reported by their owners to display more frequent and severe clinical signs (r = - 0.657; p = 0.022). CONCLUSION: ST values were lower in SM-affected CKCS compared to control dogs, suggesting the presence of neuropathic pain. Dogs with lower ST pelvic limb values were perceived by their owners to have more severe clinical signs classically associated with SM. Our results suggest that VFA might offer quantitative assessment of neuropathic pain in SM-affected dogs and could be useful for monitoring response to therapy in future clinical studies.

Comparison of high-field MRI and multidetector CT for grading Chiari-like malformation and syringomyelia in Cavalier King Charles Spaniels.

Chiari-like malformation (CM) and syringomyelia (SM) are common illnesses that can cause debilitating neuropathic pain in Cavalier King Charles spaniels (CKCS). The current imaging modality to screen CKCS for CM/SM is MRI of the brain and cervical spine. Magnetic resonance imaging provides good soft tissue detail and contrast of the cerebellum and cervical spinal cord. Computed tomography (CT) is another cross-sectional imaging technique that facilitates brain and neck evaluation; however, soft tissue resolution does not match that of MRI. Computed tomography benefits include identification of concurrent craniocervical junction anomalies (atlantooccipital overlap) and shorter imaging/anesthesia times with the ability to use only sedation. The aim of this retrospective, method comparison study is to assess the utility of multidetector CT for screening CM and SM in CKCS as compared to high-field MRI. Three groups of observers with different levels of experience graded CM and SM based on the British Veterinary Association/Kennel Club CM/SM classification criteria. Thirty CKCS underwent multidetector CT and 3 Tesla MRI studies. Computed tomography and MRI studies were reviewed at different timepoints to minimize bias. Computed tomography has lower Cohen's Kappa agreement for each observer group compared to MRI. The intraclass correlation coefficient averaging CM and SM for all groups was excellent using MRI, while CT was poor for SM and moderate for cerebellar herniation. Greater observer experience resulted in a higher agreement for CT and MRI. Magnetic resonance imaging should remain the standard for screening of CM and SM as CT can result in misclassification and greater disagreement.

A novel two-catheter method for urethral catheterization improves success rates of urethral catheterization in female dogs and cats weighing less than ten kilograms.

OBJECTIVE: To compare the success rates for urethral catheterization in clinical patients using the traditional and 2-catheter techniques when placed by personnel of all experience levels. ANIMALS: 38 female cats and dogs weighing less than 10 kg were prospectively enrolled. METHODS: Enrolled animals were randomized to have a urethral catheter placed by the traditional technique or the 2-catheter method under sedation or general anesthesia. Any qualified hospital personnel of any experience level were allowed to place the catheter. If after 5 minutes the animal was not successfully catheterized, the alternate method was performed. The previous experience of the catheter placer, animal signalment, animal condition that necessitated catheter placement, time to successful placement, and which technique was successful was recorded. RESULTS: The 2-catheter technique was more successful than the traditional method (60.5% and 34.2%, respectively) for urethral catheterization when used by a variety of hospital personnel. The 2-catheter technique was successful in 63.3% of dogs and 66.6% of cats, while the traditional method was successful in 36.6% of dogs and 33.3% of cats. Eight of 9 (88.9%) novice catheter placers that placed their first urinary catheter in this study succeeded with the 2-catheter technique and only 1 was successful with the traditional method. CLINICAL RELEVANCE: The 2-catheter technique has a higher rate of success for placement of female urinary catheters in small patients that are unable to have concurrent digital palpation. This technique may also be helpful in the inexperienced catheter placer population to aid in guidance into the urethral papilla.

Developing a predictive model for spinal shock in dogs with spinal cord injury.

BACKGROUND: Reduced pelvic limb reflexes in dogs with spinal cord injury typically suggests a lesion of the L4-S3 spinal cord segments. However, pelvic limb reflexes might also be reduced in dogs with a T3-L3 myelopathy and concurrent spinal shock. HYPOTHESIS/OBJECTIVES: We hypothesized that statistical models could be used to identify clinical variables associated with spinal shock in dogs with spinal cord injuries. ANIMALS: Cohort of 59 dogs with T3-L3 myelopathies and spinal shock and 13 dogs with L4-S3 myelopathies. METHODS: Data used for this study were prospectively entered by partner institutions into the International Canine Spinal Cord Injury observational registry between October 2016 and July 2019. Univariable logistic regression analyses were performed to assess the association between independent variables and the presence of spinal shock. Independent variables were selected for inclusion in a multivariable logistic regression model if they had a significant effect (P ≤ .1) on the odds of spinal shock in univariable logistic regression. RESULTS: The final multivariable model included the natural log of weight (kg), the natural log of duration of clinical signs (hours), severity (paresis vs paraplegia), and pelvic limb tone (normal vs decreased/absent). The odds of spinal shock decreased with increasing weight (odds ratio [OR] = 0.28, P = .09; confidence interval [CI] 0.07-1.2), increasing duration (OR = 0.44, P = .02; CI 0.21-0.9), decreased pelvic limb tone (OR = 0.04, P = .003; CI 0.01-0.36), and increased in the presence of paraplegia (OR = 7.87, P = .04; CI 1.1-56.62). CONCLUSIONS AND CLINICAL IMPORTANCE: A formula, as developed by the present study and after external validation, could be useful for assisting clinicians in determining the likelihood of spinal shock in various clinical scenarios and aid in diagnostic planning.

Understanding and Treating Chiari-like Malformation and Syringomyelia in Dogs.

Chiari-like malformation (CM) and syringomyelia (SM) are common and debilitating conditions in toy and small breed dogs. CM, considered ubiquitous in the cavalier King Charles spaniel (CKCS) population, results in abnormal cerebrospinal fluid dynamics which can lead to the development of SM. The clinical signs associated with CM/SM are frequently confused with other otologic and dermatologic conditions, which may delay appropriate treatment. A definitive diagnosis of CM/SM requires advanced imaging; however, due to expense associated with this, many cases are managed presumptively and symptomatically for the condition. The primary goal of treatment is to manage neuropathic pain and neurologic deficits through pharmaceutical or surgical approaches. Current literature suggests that most CM/SM-affected dogs have progression of their clinical signs in spite of medical or surgical management; however, most maintain a good quality of life based on owner assessments. Lack of correlation between structural markers of disease and clinician and owner-derived measures of neuropathic pain highlight the need for more robust, quantitative measures of pain in this common veterinary disease.

Presumed lupus erythematosus cells identified in bronchoalveolar lavage fluid from a Mexican Hairless dog.

A neutered male Mexican Hairless dog was presented for generalized weight loss and weakness. Initial laboratory testing and diagnostic imaging revealed thrombocytopenia and an interstitial to miliary lung pattern affecting all lung fields. Mild joint effusion was found on physical examination affecting the stifle, tarsal, carpal, and elbow joints. Examination of synovial fluid demonstrated an inflammatory polyarthropathy in 3 joints. Cytocentrifuged and direct preparations of the bronchoalveolar lavage (BAL) fluid sample were made and cells consistent with lupus erythematosus (LE) cells and ragocytes were found. Based on these findings, the anti-nuclear antibody (ANA) titer was determined as 1:640. A clinical diagnosis of systemic LE was made based on the satisfaction of 2 major criteria (thrombocytopenia and inflammatory polyarthritis), 4 minor criteria (central nervous system signs, lymphadenopathy, fever of unknown origin, and pleuritis), positive ANA titer, and the identification of presumed LE cells in BAL fluid. This case report highlights a novel finding of LE cells in respiratory secretions and provides a review of diagnostic criteria of systemic LE.