Feasibility for Measuring Transverse Area Ratios and Asymmetry of Lumbosacral Region Paraspinal Muscles in Working Dogs Using Computed Tomography

Open-Source Image Analysis Software Yields Reproducible CT Measures of Longissimus Muscle Area and Density in Sheep

Longissimus muscles (LM) in sheep are important for animal scientists who study meat quality and translational researchers who study thoracolumbar spinal disease. Computed tomography (CT) is an established technique for characterizing paraspinal muscles in sheep; however, studies reporting reproducibility of CT measures using open-source software are lacking. The objectives of this prospective pilot study were to develop a standardized protocol for measuring LM area and density in sheep using CT and to determine the reproducibility for measurements. Thoracolumbar CT images were acquired for four sheep at five time points each as part of another study. Six observers applied a standardized CT image analysis protocol to record triplicate transverse area (cm2) and water phantom-corrected mean density (Hounsfield units, HU) values for the left and right LM. Average coefficients of variation (CVs) for 4 of 6 observers were good to excellent (<10%) for all variables. Average CVs did not differ among observers for 3 of 4 variables (ANOVA, p > .05).

Evaluation of Paraspinal Musculature in Small Breed Dogs with and without Atlantoaxial Instability Using Computed Tomography

OBJECTIVE

 The aim of this study was to evaluate differences in paraspinal musculature between dogs with and without atlantoaxial instability (AAI) using computed tomography scans.

STUDY DESIGN

 Retrospective multicentre study evaluating transverse reconstructed computed tomography scans of 83 small breed dogs (34 with and 49 without AAI) for the cross-sectional paraspinal musculature area at three levels (Occiput/C1, mid-C1, mid-C2). Ratio of moments, dorsal-to-ventral muscle-area ratios (d-v-ratio) and ratios of the dorsal and ventral musculature to C2 height (d-C2-ratio and v-C2-ratio) were evaluated for differences between groups using multivariate analysis of variance (p < 0.05) taking the head-neck position into account.

RESULTS

 Dogs with AAI showed a significantly lower d-v-ratio at levels 2 and 3, d-C2-ratio at level 2 and ratio of moments at all levels. When head-neck positions were analysed separately, ratio of moments was significantly lower in affected dogs at level 1 and 2. Also lower was d-C2-ratio at level 2, but only in flexed positioning. The head-neck position had a significant influence on ratio of moments and d-v-ratio at all three levels and on d-C2-ratio at level 1.

CONCLUSION

 Significant changes in muscle area were observed only for the hypaxial muscles at the C1 level, indicating a limited role of muscular adaption in AAI patients. Our results confirm an altered ratio of moments in dogs with AAI. The head-neck position has a significant impact and should be taken into account when evaluating spinal musculature.

Sports Medicine and Rehabilitation in Working Dogs

Canine sports medicine and rehabilitation recently have evolved to embody the optimization of performance, injury prevention, and mitigation of musculoskeletal degeneration. This article discusses the diverse factors and considerations of working dog wellness and injury prevention and the importance of recognizing normal and abnormal posture and anatomic structure for performance evaluation and early indication of musculoskeletal injury. The importance of a canine physical fitness program is highlighted and the need for a 4-phase recovery plan to determine if a working dog can safely return to work after injury discussed.

Observational Study on Lameness Recovery in 10 Dogs Affected by Iliopsoas Injury and Submitted to a Physiotherapeutic Approach

Simple Summary

Acute trauma of the iliopsoas muscle is often observed in sports and very active dogs. Nevertheless, the diagnosis is not always correctly addressed and can be underestimated during a clinical visit because it is generally secondary to other orthopedic and neurological issues. However, a correct diagnosis can lead to complete recovery of lameness in dogs who submit to physiotherapy. This paper has investigated, in a preliminary observational study, the recovery time for dogs affected by primary iliopsoas lesions and their return to normal activity.

Abstract

This preliminary study has investigated the outcome of physiotherapy in 10 dogs affected by a primary lesion of the iliopsoas muscle and the potential effects of sex, age, and breed on recovery. Ten dogs with primary injury of the iliopsoas muscle were retrospectively included in this study. Dogs were submitted to a rehabilitation program, characterized by a multimodal approach, including physical therapies and modalities. After recovery, patients were submitted to a further support period of rehabilitation to promote muscle strengthening and limit injury recurrence during their return to normal functional and sports activity. Border collies were highly represented. The recovery of lameness occurred after a mean of 22.6 ± 14.7 (median 18) days with a median number of five sessions. None of the examined variables affected the recovery time, except for the border collie breed, which showed a significantly faster recovery time; however, there was no difference between the breeds with regard to the number of sessions. Multimodal rehabilitation therapy may promote lameness recovery of mild-to-moderate iliopsoas lesions within 3 weeks. This preliminary study reports a clinical approach and recovery of primary iliopsoas lesions, findings that can provide clinicians with useful prognostic information for dogs involved in sports activities.

The Penn Vet Working Dog Center Fit to Work Program: A Formalized Method for Assessing and Developing Foundational Canine Physical Fitness

Fit to Work is a formalized working dog foundational physical fitness assessment and development program. The Penn Vet Working Dog Center developed this program to address the needs of working dog handlers, trainers, and programs for simple, effective, and efficient methods to develop and assess working dog physical fitness. Fit to Work focuses on the foundational fitness modalities of strength, stability, mobility, and proprioception. The Penn Vet Working Dog Center piloted and refined this program over 3 months in a closed population of 31 working dogs in training. Fit to Work consists of posture development and maintenance, warm-up and cool-down routines, training exercises, and assessment methods. To simplify implementation for dogs and personnel, the foundational training program incorporates a discrete number of exercises, standardized progression steps, defined criteria for progression, and a reduced emphasis on learned behaviors. Fit to Work also enables safe and progressive assessment of foundational fitness through a tiered and inexpensive process. Future research will focus on validation of training and assessment methods, development of assessment standards, and correlation of physical fitness with operational performance.

CT measures of lumbosacral paraspinal muscle size are not correlated with CT measures of lumbosacral stability in military working Labrador Retrievers

Management of degenerative lumbosacral stenosis in military working dogs more frequently utilizes core conditioning exercise programs. Future research on the effectiveness of these programs may benefit from an improved understanding of relationships between paraspinal muscle size and lumbosacral stability. The aim of this retrospective, secondary analysis, cross-sectional study was to test the following hypotheses related to CT measures: (a) transverse paraspinal muscle area ratios differ between hip flexion and extension, (b) lumbosacral angle and lumbosacral range of motion differ by lumbosacral angle measurement technique, and (c) transverse paraspinal muscle area ratios are correlated with CT measures of lumbosacral stability (parasagittal and parasagittal oblique foraminal area changes) regardless of hip position and with lumbosacral range of motion within each hip position. Lumbosacral CT scans in hip flexion and extension were retrieved from a previous prospective study of military working Labrador Retrievers. A single observer performed triplicate measurements of transverse paraspinal muscle area ratios, parasagittal foraminal area, and parasagittal oblique foraminal area for each hip position and another observer independently performed triplicate measurements of lumbosacral angle and lumbosacral range of motion at L7-S1 using two published techniques. Thirty-nine dogs were analyzed and significant differences were identified between hip flexion and extension for all mean transverse paraspinal muscle area ratio values (P ≤ .05). Mean lumbosacral angles also significantly differed between the published techniques in both hip flexion and extension. When comparing mean lumbosacral range of motion values, one of the published techniques produced significantly smaller values. No significant correlation was found between transverse paraspinal muscle area ratios and parasagittal foraminal area changes, parasagittal oblique foraminal area changes, or lumbosacral range of motion. These results should be considered when designing studies using these CT measures in military working dogs.

Cross-sectional area and fat content in dachshund epaxial muscles: an MRI and CT reliability study

MRI and CT are frequently used to diagnose spinal diseases in dogs. These modalities have detected epaxial muscle degeneration in dachshunds with intervertebral disc herniation. However, research on the reliability of epaxial muscular measurements is limited in veterinary medicine. The aims of the study were to assess the intrarater and inter-rater reliability of epaxial muscle cross-sectional area (CSA) and fat content measurements on MRI and CT images in dachshunds, and to compare the CSA measurement between the two modalities. MRI and CT images of 10 healthy dachshunds were evaluated. Two blinded observers assessed MRI CSA, MRI fat content, CT CSA and CT muscle attenuation of three thoracolumbar epaxial muscles using OsiriX. The results showed ‘substantial’ to ‘almost perfect’ intrarater reliability (intraclass correlation coefficient (ICC) 0.828–0.998) and inter-rater reliability (ICC 0.685–0.854) for all variables. When individual spinal segments were analysed, the intrarater and inter-rater reliability decreased and the confidence intervals increased. There was positive correlation (r= 0.719–0.841, P=0.001) and high agreement (0.824–0.894) for the measured CSA between MRI and CT. Epaxial muscle CSA and fat content can be reliably measured on MRI and CT, bearing in mind that measurement of certain segments requires adequate training.