Epaxial muscle atrophy is more evident in large dogs with intervertebral disc disease than in dogs with ischaemic myelopathy.

Cross-sectional area (CSA) decreases and fat infiltration increases in epaxial muscles of Dachshunds with intervertebral disc disease (IVDD), but less is known about large breed dogs with IVDD. The aim here was to investigate thoracolumbar epaxial muscle CSA and fat infiltration in large breed dogs with compressive IVDD and acute non-compressive nucleus pulposus extrusion (ANNPE) or fibrocartilaginous embolism (FCE). This retrospective study included large breed dogs with MRI-confirmed IVDD (n = 17) and ANNPE or FCE (n = 13). The CSA and fat infiltration of the thoracolumbar M. longissimus and Mm. multifidi were assessed from T1-weighted transverse MR images using Osirix. The CSA was significantly smaller in dogs with compressive IVDD than in dogs with non-compressive ANNPE or FCE for Mm. multifidi (p = 0.015), M. longissimus (p = 0.070), and these two muscles combined (p = 0.016). Fat infiltration in all muscle measurements was significantly higher in dogs with compressive IVDD than in dogs with non-compressive ANNPE or FCE (all P < 0.050). A significant positive correlation existed between age, duration of clinical signs, and fat infiltration, suggesting more fat infiltration in older dogs with more chronic signs. These signs of muscle atrophy are likely caused by denervation and secondary disuse due to chronic spinal cord compression and prolonged duration of clinical signs.

The Finnish Canine Stifle Index: responsiveness to change and intertester reliability.

BACKGROUND: The responsiveness and the intertester reliability of the Finnish Canine Stifle Index (FCSI) were tested, and a cut-off between compromised and severely compromised performance level was set. METHODS: Three groups of dogs were used, 29 with any stifle dysfunction (STIF), 17 with other musculoskeletal disease except stifle (OTHER) and 11 controls (CTRL). All dogs were tested with the FCSI by the same physiotherapist at three occasions, at baseline, at six weeks and 10 weeks, and once also by another physiotherapist. RESULTS: Dogs in the STIF group demonstrated significantly higher (P<0.001) FCSI scores than in OTHER or CTRL groups at baseline. Only the STIF group showed a significant (P<0.001) change in FCSI score at all time points, indicating responsiveness to change. There were no significant differences between the evaluators (P=0.736), showing good intertester reliability, supported by moderate to good (0.78) intraclass correlation coefficient (ICC). The evaluator performing the FCSI did not have a significant effect when comparing the groups of dogs (P=0.214). The 95 per cent confidence intervals of the ICC per group were 0.79 (0.60, 0.91) for STIF, 0.83 (0.53, 0.96) for OTHER 0.78 (0.64, 0.88) for all dogs. A cut-off differentiating a severely compromised from a compromised performance was set at 120, having sensitivity of 83 per cent and specificity of 89 per cent. CONCLUSION: The FCSI is a recommendable measure of dogs' stifle functionality.

Comparison of cross sectional area and fat infiltration of the epaxial muscles in dogs with and without spinal cord compression.

This study investigated the cross sectional area (CSA) and fat infiltration of the epaxial muscles in Dachshunds with compressive spinal cord lesions due to intervertebral disc herniation (IVDH) and in dogs with non-compressive spinal cord lesions with fibrocartilaginous embolism (FCE). The CSA and fat infiltration of the multifidi and longissimus dorsi muscles were determined from T1 weighted magnetic resonance images. Difference in CSA and fat infiltration between the lesion- and non-lesion side in the Dachshunds was assessed using mixed model analysis. Difference in CSA and fat infiltration between Dachshunds and FCE dogs was analysed with independent sample t-tests. There was no difference in CSA or fat infiltration between sides in the Dachshunds. FCE dogs had greater CSA (multifidus P = 0.036, longissimus P < 0.001) and less fat infiltration compared to Dachshunds (longissimus P = 0.017). Duration of neurological deficits, age, body size and conformation are likely to have influenced the difference between the groups.