Investigation of cervical pain in the performance horse
Recently it has been identified abnormalities in the cervical vertebral column and associated soft tissues such as muscle, ligaments, and nerves can seriously compromise performance. For several years, most abnormalities of the cervical vertebral column have been associated with neurological dysfunction mainly ataxia (incoordination). However, other signs such as cervical pain, reduced cervical flexion and extension, weakness and lameness of the front limbs, and reduced performance can be commonly observed.
Abnormalities of the cervical vertebral column can be congenital or acquired. Congenital abnormalities that involved the vertebral column have been observed in certain breeds of horses such as Warmbloods. The focus of our studies is to investigate the presence of anatomical variations in horses used for high performance with and without signs of dysfunction or pain. These studies include clinical evaluation (lameness and neurological examination) and imaging of the neck (radiography, computed tomography).
Prevalence of cervical caudal malformation and association with vertebral canal stenosis and articular process osteoarthrosis in the horse
DeRouen A, Spriet M, Aleman M. Vet Radiol Ultrasound 2016;57(3):253-258.
The sixth cervical vertebra (C6) has unique morphology due to a ventral extension from the transverse process known as the ventral lamina. Little information was found regarding the prevalence and clinical relevance of morphologic variations. Aims of this observational, retrospective study were to characterize C6 morphologic variations in a large sample of horses. Cervical radiographic studies of 100 horses were retrieved. Data recorded were signalment, clinical history, morphology of the C6 ventral lamina, presence of articular process osteoarthritis, and presence of static vertebral canal stenosis. Morphologic variations were found in C6 vertebrae for 24/100 horses, with symmetric absence of the ventral lamina in nine horses and asymmetric absence in 15. Anomalous C6 vertebrae were more common in Warmbloods, with 19/55Warmbloods in the population being affected (P = 0.006). No association was found with sex. There was no significant difference in the mean of the intravertebral sagittal ratios between horses with normal or anomalous C6 vertebrae; however there was a significantly greater proportion of horses with anomalous C6 vertebrae that had an intravertebral sagittal ratio of less than 0.5 at C6 (P = 0.047). There was no association between the morphology of C6 and articular process osteoarthritis. Anomalous C6 vertebrae in our population were associated with a higher likelihood of cervical pain (P = 0.013). Authors propose that morphologic variations in the C6 ventral laminae could be linked to other developmental abnormalities such as vertebral canal stenosis, might affect regional biomechanics and should therefore be considered clinically relevant in horses. Future, controlled prospective studies are needed to test this theory. http://onlinelibrary.wiley.com/doi/10.1111/vru.12350/pdf