Mar Vista Animal Medical Center

3850 Grand View Blvd.
Los Angeles, CA 90066



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Spinal surgery is highly invasive, very expensive, and with both potential for great outcome as well as poor outcome depending on the damage already sustained by the spinal cord. Patients are generally not candidates for surgery unless they cannot walk, have only been paralyzed for a few days at most, and, of course, have a disease (such as disk herniation) where there is pressure on the spinal cord that can be relieved surgically. There is frequently a great deal of nursing care following surgery along with physical therapy. Spinal surgery may be performed on an emergency basis such as after an acute Hansen Type I episode or it may be performed in a more chronic situation such as to relieve long-standing pain. The goal of surgery in either case is to relieve pressure on the spinal cord when there is pressure from an external source (i.e. herniated disk material pressing on the spinal cord or perhaps a tumor or bone pressing against the spinal cord.) The most common scenario is to remove herniated disk material.

The first step will be localizing the area of the compression. A patient may have several areas of disk disease but the surgeon will need to know which one is the active one. This will require some kind of advanced imaging such as CT scanning, MRI imaging, or myelography. The patient commonly goes directly to surgery after imaging without being awakened from general anesthesia.

Several procedures can be used to decompress the spinal cord and remove the disk material. Several common procedures one may hear about are: hemilaminectomy, pediculectomy, dorsal laminectomy, ventral slot, and fenestration. 


This is most commonly performed on disk herniations in the thoracolumbar area. In this surgery the articular facets (where the two vertebrae connect) are removed as is the vertebral bone adjacent to the spinal cord. This procedure can safely be performed over up to 5 adjacent disk spaces.

“Aerial” view of vertebrate.


“Aerial” view of vertebrate. See how the bone has been removed to make room for the swollen spinal cord and nerve root. Herniated disk material can also be removed. This is called a hemi laminectomy because surgery is performed on one side. The spinal cord and nerve roots are shown in gold.

(original graphic by



Similar to hemilaminectomy except only the articular facets are preserved. This is best performed when the disk herniation is slightly off to the side rather than straight upward. This procedure is less invasive and less destabilizing to the vertebrae than is hemilaminectomy.

“Pedicular” bone is removed from the vertebrae to create room for the spinal cord but the articular facets are preserved above.

“Pedicular” bone is removed from the vertebrae to create room
for the spinal cord but the articular facets are preserved above.
Spinal cord is shown in gold.
(original graphic by

Dorsal Laminectomy

This is probably the most invasive of all the procedures and involves decompressing the spinal cord from the top rather than from the bottom. It can only be done over one disk space and involves removing the dorsal spinous process and lamina as shown on the right. This technique is common for lumbar disks.


Graphic showing entire top of vertebra has been removed to make room for swollen spinal cord.

Entire top of vertebra has been removed
to make room for swollen spinal cord
(original graphic by


Ventral Slot

This procedure is reserved for neck disks. Here a slot is drilled in the vertebral bodies of the bones on either side of the disk creating a small window over the disk space. Mineralized disk material can be removed and, since the window includes adjacent bone, there is room for the swollen spinal cord to decompress. Disks in the neck present a unique situation in that the disk can be approached from the throat side or the nape/scruff side. The ventral slot uses a throat side approach.



This is a preventive procedure often performed on the disk spaces near the herniated space. It involves making a slit over the annulus fibrosus and removal of any mineralized nucleus pulposus. In other words, a slit is made in the soft area between vertebrae so that any disk material will herniate away from the spinal cord as it follows the path of least resistance. For some patients, this is the only surgery needed but it is not truly a decompressive surgery. Whether or not fenestration truly reduces the chance of recurrence of signs is a controversial subject.


Recovery after Surgery

The goal of surgery is to restore the pet’s quality of life. In most cases this means return of the ability to walk. How long it takes the patient to walk again after surgery is highly dependent on how much dysfunction was present prior to surgery. Patients with voluntary motor control commonly recover the ability to walk within 2 weeks while those with deep pain but no voluntary motor control might require up to 4 weeks. Nursing care for a dog that cannot walk can be intense including expressing the patient’s bladder, keeping the patient bedded, and performing physical therapy exercises. Check with your surgeon regarding proper physical therapy exercises and details with regard to toileting during recovery.



Spinal surgery does not always work out. Sometimes it simply too expensive. Sometimes there is simply too much damage to the spinal cord to get good return to function. In these situations, the patient may end up unable to use his or her back legs. Taking care of a dog that is “down in back” is a big project definitely not something that every dog owner is able to commit to.. Still, it can be done and for the right dog and the right person, it is a highly rewarding experience. A great deal of progress can often be made using physical therapy exercises as described in the medical management section plus there are a number of resources and products available to assist in the care of the immobile pet. Click here for more information on what is involved in this situation.

Dog in walking device
(Photocredit: Pozytyv via Wikimedia Commons)



Physical therapy for pets is a relatively new field of specialization and we are finding that rehabilitation exercises make a huge difference to patient comfort and ability in many situations. Our area is fortunate enough to have several rehabilitation clinics where therapy programs can be devised and/or carried out. We will be happy to refer you.

To find a physical therapist for your pet outside of the Los Angeles area, please use this link:

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Page last revised : 422/2023