Introduction: Male German Shepherd dogs (GSD) are widely used as working dogs. Training iscommonly started without previous radiological examination. Predisposition to cauda equinasyndrome (CES) and hip dysplasia (CHD) is common in GSD and may lead to premature losses. Purpose: To define the status of the LS articulation in all working GSD of the Zurich state police.Dogs were screened neurologically and radiographically in order to1. assess neurological and radiological changes in the lumbosacral articulation and in the hipjoints utilizing basic neurological tests and plain radiographs,2. correlate the neurological findings with radiological findings,3. establish a pre training examination protocol of the LS area, if possible.Material and methods: 60 working GSD of the Zurich state police were examined neurologicallyand radiographically. The dogs were between 1 and 9 years old, 53 animals were male, 7 female,and the body weight ranged from 29 to 45 kg. Workup included a complete history, neurologicalexamination, and 2 radiographs of the LS area in a non stressed position and 1 of the hip joints inextended position taken in deep sedation. Radiographs were evaluated for developmental and/ordegenerative changes of the LS junction and hip joints. The results were statistically evaluatedusing chi square- and student’s t-tests and stepwise backwards multivariate regression-models.
Results: Clinical findings compatible with CES were noted in 23/60 dogs, 8 of them considered tobe normal by their owners. Findings were more common in older dogs (p<0.05). The mostconsistent finding was painful LS hyperextension (20/23). Radiological LS changes were found in39/60 dogs, 17 of them showing clinical signs of CES. LS spondylosis formation was the mostcommon finding (23/60 dogs) affecting older dogs more often. The incidence of clinical symptomsincreased with progressive degree of spondylosis (p<0.05). Signs of disk degeneration was noted in24/60 dogs. Transitional vertebrae were seen in 2/60, 1 of them showing clinical signs of CES. Nosigns of LS OCD were found. Of the 60 dogs 16 showed mild to severe CHD, 8 of them alsoclinical symptoms of CES. With increasing severity of CHD there was also increasing incidence ofspondylosis.Stepwise backwards multivariate regression revealed 3 predictors for clinical symptoms (accuracy87%): middle to old age, presence of spondylosis and of a lumbosacral step formation.
Discussion/Conclusion: An incidence of 38% clinical signs of CES and of 65% radiological signsof LS degeneration is undesirable in a performance-orientated canine population. Compared toliterature our data show a high incidence of LS degeneration with spondylosis formation as the mostfrequent finding with a sensitivity of 56% and a specificity of 73%. A similar incidence of clinicalsigns of CES has been only reported in hospital patients, so far. On the other hand, congenital ordevelopmental malformations (transitional vertebrae, OCD, CHD) are seen less frequently in ourpopulation when compared to literature data. Pre selection of dogs on gender and possibly also onperformance in our study prevents to define objectively selecting criteria for working dogs. It isadvised to determine radiological criteria for a disposition to CES in order to evaluate futureworking dogs prior to training. Predictors for CES in young dogs without degenerative LS changesshould be established by means of sequential studies.