MAGNETIC-RESONANCE-IMAGING OF PRESUMPTIVE LUMBOSACRAL DISCOSPONDYLITIS IN A DOG

A three-year-old male Boxer dog had hyperesthesia, symmetrical epaxial , gluteal and hind limb muscular atrophy and rear limb ataxia, Neurolo gical deficits included decreased conscious proprioception of the left hind limb, decreased withdrawal and increased patellar reflexes of bo th hind limbs, The dog had a urinary tract infection with positive cul ture for Staphylococcus intermedius. On survey radiography of the lumb osacral spine there was active bone proliferation spanning the L7 S1 i ntervertebral disc space with an epidural filling defect at the ventra l aspect of the vertebral canal on epidurography. On magnetic resonanc e imaging (MRI), findings were similar to those described for human di skospondylitis including altered signal intensity and nonuniform contr ast enhancement of the L7-S1 intervertebral disc, adjacent vertebral e nd plates and epidural and sublumbar soft tissues, Although skeletal r adiography is usually sufficient to reach a diagnosis of discospondyli tis, MRI of this patient made it possible to reach a presumptive diagn osis of discospondylitis prior to development of definitive radiograph ic abnormalities.