Validation of a novel clinical tool for monitoring distal limb stiffness.

Objective: To validate a novel technique to measure limb stiffness in a clinical setting. Animals: Three horses and three ponies owned by the Royal Veterinary College. Procedures: Limb stiffness indices for both forelimbs were first derived using the gold standard of kinematic analysis. Using the same animals, limb stiffness indices were then calculated using portable floor scales to record weight and an electrogoniometer to record changes in metacarpophalangeal joint angle. The two techniques were then assessed for correlation and repeatability. Results: The repeatability of limb stiffness measurement using the novel clinical tool was considered to be good based on a small coefficient of variation (5.70%). The correlation of limb stiffness as derived by both methods was high (r = 0.78, p < 0.01). Limb stiffness was positively correlated with the mass of the subject (r = 0.85, p < 0.01), with heavier horses having greater limb stiffness. Clinical relevance: This study has compared a novel method to measure distal forelimb stiffness non-invasively in a clinical setting to kinematic analysis in six equids. It has demonstrated that limb stiffness increases in a linear fashion with body mass consistent with the role of forelimbs providing energy storage. Because in vivo limb stiffness has been shown previously to alter with injury to the superficial digital flexor tendon, it is hypothesized that this technique will offer a practical technique for the clinician to assess limb stiffness in clinical cases. Further study will be necessary to determine its clinical usefulness in such cases.

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.

Results of oral prednisolone administration or ventriculoperitoneal shunt placement in dogs with congenital hydrocephalus: 40 cases (2005-2016).

OBJECTIVE: To evaluate signalment, clinical findings, and outcomes of dogs with congenital hydrocephalus treated medically with orally administered prednisolone or surgically by ventriculoperitoneal shunt placement. DESIGN: Retrospective case series. ANIMALS: 40 client-owned dogs. PROCEDURES: Medical records from 2005 to 2016 were searched to identify dogs with congenital hydrocephalus confirmed by MRI examination. Patients were categorized by treatment (medical vs surgical). Signalment, clinical signs, neurologic examination findings, results of diagnostic tests, duration of hospitalization, complications potentially related to treatment, and follow-up information were recorded. Outcome was categorized on the basis of clinical (neurologic) signs as improved, stabilized, or deteriorated. Variables of interest were compared between groups by Fisher exact or Mann-Whitney U tests. RESULTS: 28 and 12 dogs had surgical and medical treatment, respectively; 3 medically treated dogs subsequently underwent ventriculoperitoneal shunt placement. No significant differences were noted in clinical or imaging findings between surgically and medically treated dogs. Median follow-up time was 9 months and 15.5 months for medically and surgically treated dogs, respectively. Of 12 medically treated dogs, 6 improved and 6 deteriorated. Of 26 surgically treated dogs with data available, 14 (54%) improved, 1 (4%) stabilized, and 11 (42%) deteriorated; 4 (15%) had known postoperative complications. CONCLUSIONS AND CLINICAL RELEVANCE: Approximately half of the dogs treated with prednisolone in this population had neurologic improvement at last follow-up; results of surgical treatment were comparable to those in previous studies. Further research is needed to assess factors associated with acceptable outcomes for dogs with congenital hydrocephalus.

Prognostic Factors for Recovery of Vision in Canine Optic Neuritis of Unknown Etiology: 26 Dogs (2003-2018).

Optic neuritis (ON) is a recognized condition, yet factors influencing recovery of vision are currently unknown. The purpose of this study was to identify prognostic factors for recovery of vision in canine ON of unknown etiology. Clinical databases of three referral hospitals were searched for dogs with presumptive ON based on clinicopathologic, MRI/CT, and fundoscopic findings. Twenty-six dogs diagnosed with presumptive ON of unknown etiology, isolated (I-ON) and MUE-associated (MUE-ON), were included in the study. Their medical records were reviewed retrospectively, and the association of complete recovery of vision with signalment, clinicopathologic findings, and treatment was investigated. Datasets were tested for normality using the D'Agostino and Shapiro-Wilk tests. Individual datasets were compared using the Chi-squared test, Fisher's exact test, and the Mann-Whitney U-test. For multiple comparisons with parametric datasets, the one-way analysis of variance (ANOVA) was performed, and for non-parametric datasets, the Kruskal-Wallis test was performed to test for independence. For all data, averages are expressed as median with interquartile range and significance set at p < 0.05. Twenty-six dogs met the inclusion criteria. Median follow-up was 230 days (range 21-1901 days, mean 496 days). Six dogs (23%) achieved complete recovery and 20 dogs (77%) incomplete or no recovery of vision. The presence of a reactive pupillary light reflex (p = 0.013), the absence of fundoscopic lesions (p = 0.0006), a younger age (p = 0.038), and a lower cerebrospinal fluid (CSF) total nucleated cell count (TNCC) (p = 0.022) were statistically associated with complete recovery of vision. Dogs with I-ON were significantly younger (p = 0.046) and had lower CSF TNCC (p = 0.030) compared to the MUE-ON group. This study identified prognostic factors that may influence complete recovery of vision in dogs with ON. A larger cohort of dogs is required to determine whether these findings are robust and whether additional parameters aid accurate prognosis for recovery of vision in canine ON.