Intervertebral disc disease occurs predominantly on middle-aged (3 to 6 years old) canine chondrodystrophic breeds. When you say chondrodystrophy, it is a disorder of cartilage formation. It is characterized by deformities in the angular limb deformities and abnormally short legs or otherwise known as hereditary dwarfism.
Intervertebral discs disease, particularly degeneration of discs is further classified into two types: (a) HANSESN TYPE I that which includes chondroid degeneration with extrusion of nuclear material brought about by dorsal annulus fibrosus rupture and the dorsal longitudinal ligament rupture into the verterbral canal. (b) HANSEN TYPE II- fibroid degeneration with protrusion or bulging of the partially thickened and ruptured annulus fibrosus.
The most common site of cervical disc herniation is between C2/C3. This area is the most commonly affected.