How does IVDD in large breed dogs differ from that in small chondrodystrophic breeds?
Large breed dogs rarely have disk extrusions (pushing of the nucleus through the annulus and into the spinal canal) that are common in small chondrodystrophic breeds. Disk extrusions in small breeds are classified as Hansen Type 1 Disk Disease. Large breed dogs more frequently have a build up of scar tissue over the outer layer of the disk (the annulus) that pushes up on the spinal cord and gradually causes pain and weakness. This condition is classified as Hansen Type 2 Disk Disease. Hansen Type 2 Disk Disease causes slowly progressive neurologic impairment. These dogs are usually older and may not be as painful as the small breeds with Type 1 disease. Surgical therapy for Type 2 disease may not be as successful for large breed dogs and recovery commonly takes longer than for small dogs. Hansen Type 2 Disk Disease must be differentiated from other causes of neurologic dysfunction that also affects principally large breed dogs such as Degenerative Myelopathy, Diskospondylitis or Fibroc
