

Because the annulus fibrosus is so thick, an outer tear does not typically occur, so the nucleus pulposus does not spill through it to infringe upon the spinal cord directly. Hansen Type II Disc Degeneration occurs due to dehydration and thickening of the annulus fibrosus (i.e. This type of IVDD is generally acute (or sudden) in nature. herniated, or slipped disc) occurs due to dehydration and calcification (chondroid metaplasia, to be technical) of the intervertebral disc over time secondary to the factors addressed previously. The prolapsed material then pushes up against the spinal cord and/or nearby nerve roots, causing the “downstream” nerve dysfunction (and pain!) that we mentioned prior.

Hansen Type I Disc Degeneration results in rupture of the annulus fibrosus, causing sudden extrusion of the nucleus pulposus through this tear. IVDD may arise primarily from one of two scenarios: Hansen Type I Disc Degeneration or Hansen Type II Disc Degeneration. Eventually, the damage to the disc is so great, that it eventually fails, leading to an IVDD problem.Īny region of the spine may be affected, though the area between the 3rd thoracic vertebra and 3rd lumbar vertebra (T3-元) are most commonly affected (primarily between T10-L2 as anatomic differences in this region cause the spine to be more unstable here, and therefore more prone to abnormal movement). These changes cause the disc to be hard rather than spongy. Such injury interferes with the cartilage composition of the disc, leading to dehydration and calcification (or mineralization) as well as impairment of its nutritional supply (which is already limited due to poor blood supply to the center of the disc, thereby interfering with healing). It occurs due to progressive damage to the intervertebral disc over time due to a variety of factors, including genetics, sudden traumatic injury, and/or chronic low-grade injury over time due to abnormal stress on the spine. Intervertebral disc disease is the most common cause of spinal cord disease (a.k.a. This type of spinal cord injury is exactly what happens with intervertebral disc disease, or IVDD: injury to one (or several) of the intervertebral discs results in compression of the spinal cord, causing pain as well as “downstream” nerve dysfunction. Therefore, the limbs will not work normally. If a certain area of the spinal cord is injured (as occurs with IVDD), approximately everything “downstream” from that location is therefore unable to receive the proper signals (nerve impulses) from the brain in order to function properly. innervate) various regions of the body, primarily the limbs. Nerves branch off the spinal cord at specific nerve root locations in order to provide nerve supply (i.e. The spinal cord acts as the “vice president” of the governing brain, transmitting the brain’s messages via nerve impulses to the rest of the peripheral body. The spinal cord, along with the brain, make up the central nervous system (CNS). (This specific anatomic arrangement will come into play later on as we discuss the causes of intervertebral disc disease, or IVDD.) Each spongy intervertebral disc is comprised of a gelatin-like center called the nucleus pulposus (this region lacks a nerve and blood supply) surrounded by a fiber-like band called the annulus fibrosus. These discs act as shock absorbers while also piecing together the individual vertebral bodies of the spine. Squishy discs of cartilage called intervertebral discs lie between each vertebrae (excluding between cervical vertebrae 1 and 2 as well as between vertebrae of the sacrum, which are fused together).

The canine spinal column is made up of 7 cervical (or neck, C1-7), 13 thoracic (or chest, T1-13), 7 lumbar (lower back, L1-7), 3 sacral (pelvic region, S1-3), and multiple coccygeal (a.k.a.
#Droppy hand disease series
The spine (or spinal column) is comprised of a vertical arrangement of vertebrae (or vertebral bodies), a series of bones that surround and protect the spinal cord. The Meowing Vet discusses why IVDD may occur in dogs or cats, other signs that pet owners should be aware of, and how this problem is diagnosed and treated. Certain dog breeds are predisposed to this neurological ailment, such as Dachshunds. Intervertebral Disc Disease (IVDD) is a “slipped disc” in the spinal column that can result in excruciating pain and possible paralysis due to compression of the spinal cord. PRINT Your dog is yelping in pain, and you notice that he is having trouble moving his back legs.
