High quality imaging and surgical technique are required to completely identify and treat a neurological problem. The CT and/or MR images obtained prior to surgery will be the “blue print” for the neurosurgeon. Most neurological surgeries are decompressive, meaning that a tumor, disk material or dislocated bone is pressing on nearby healthy tissue such as the spinal cord, nerve roots;or brain matter causing neurological deficits and possibly pain. The purpose of the surgery is to reduce this compression and alleviate the patient’s signs. Most surgeries at the Veterinary Neurological Center are performed within 2-3 hours. Patients are closely monitored during and after anesthesia. Medical treatment before, during and after surgery is necessary in order to provide the greatest probability for full patient recovery.


A laminectomy surgery is performed by removing the top of the vertebra, the lamina, to gain access to the spinal cord. The surgeon can then gently remove the protruding or ruptured disk material (or tumor) that is compressing the bottom and/or side of the spinal cord and/or nerve roots. Laminectomy surgery is often performed to treat:

  • intervertebral disk disease (neck-large dogs)
  • intervertebral disk disease (lumbosacral region)
  • spinal tumor (and biopsy)


This is a type of laminectomy in which only a portion of the lamina is removed. The pedicle (side) of the vertebra is also removed allowing the surgeon to approach the spinal cord at a side angle. Hemilaminectomy is the most common type of decompressive spinal cord surgery and is frequently performed to treat:

  • intervertebral disk disease (back)
  • spinal tumor (and biopsy)

Ventral Slot

Patients with spinal cord compression in the neck may require a ventral slot surgery which is performed from the underside of the neck. Ventral slot surgery is commonly performed to treat:

  • intervertebral disk disease (neck)


Fenestration means "to make a window" and is a preventative procedure and is often performed in conjunction with a laminectomy, hemilaminectomy or ventral slot. The procedure involves removal of the degenerative center of the non-herniated disks in front of and behind the disk that has protruded/herniated. A window is cut in the annulus fibrosus of the disk followed by extraction of the degenerative nucleus pulposus. As the resected center of the disk scars, there is little or no effect on mobility. Although unlikely, there is still potential for future ruptures of the fenestrated disk(s). Fenestrations are commonly performed on patients with:

  • intervertebral disk disease (back)
  • intervertebral disk disease (neck)

Foramen Magnum Decompression

In this procedure, a caudal occipital craniectomy +/- dorsal laminectomy of C1 is performed to treat caudal occipital malformation syndrome (COMS) in dogs. The goal of the surgery is to decompress the spinal cord and cerebellum at the level of the foramen magnum, stop the progression of the syrinx and aid the flow of cerbrospinal fluid (CSF). This is accomplished by removing the back of the occipital bone and often the top of the first few vertebrae. This provides more space for the brainstem, spinal cord and descended cerebellar components. A tissue graft may be spliced into this opening to provide even more room for the unimpeded passage of CSF. Occasionally, the cavity within the spinal cord resulting from syringomyelia can be drained with a shunt tube. This tube diverts the fluid from inside the spinal cord to outside the cord, or it can be directed to either the chest or abdominal cavity. These procedures can be done together or separately. This surgery is commonly peformed to treat:

  • caudal occipital malformation syndrome (COMS) or Chiari-like malformation
  • syringomyelia

Vertebral Stabilizations

Vertebral stabilization surgeries are performed to repair fractures, stenosis or subluxations/luxations of the vertebrae. Fractures are primarily caused by trauma while stenosis is usually due to degenerative or congenital reasons. Subluxations or luxations are often caused by a malformation of the vertebrae (often congenital) or a problem with the ligaments which hold the vertebrae in place (usually congenital and/or traumatic). Pins, screws, and/or bone cement are used to fuse parts of a vertebra or multiple vertebra together to fix the instability and alleviate pressure on the spinal cord. Diseases that may require this type of surgery are:

  • cervical spondylomyelopathy (CSM) or ‘wobbler’ syndrome
  • atlantoaxial subluxation
  • lumbosacral stenosis or cauda equina syndrome

Tumor Removal

The goal of this surgery is to remove as much, if not all, of the tumor as possible while trying to minimize damage to healthy tissue. A craniotomy is performed to gain access to the lesion. Once the tumor has been identified, the neurosurgeon at the Veterinary Neurological Center may use a fluorescent dye to highlight the tumor. Then an advanced surgical instrument, the ultrasonic aspirator, is implemented to aid in the removal of neoplastic tissue while leaving behind healthy tissue. To verify the type of cancer and help with treatment, the surgeon will submit a sample of the tumor to a pathologist for examination.

Some tumors can be removed completely, while others can be removed only partially or not at all. A combination of therapies (radiation and chemotherapy) are used to treat tumors that can’t be removed surgically or by surgery alone. Once treated, a brain tumor may remain in remission for years or may never recur. When a brain tumor is in remission, it means that tests do not show any signs of the cancer. Sometimes this means it will never return, but in other cases the cancer may be too small for tests to detect and it may recur at a later date. A repeat CT or MRI scan may be recommended to monitor for tumor regrowth. The most common brain tumor to be treated surgically is:

  • meningioma

Ventriculoperitoneal Shunt Surgery

Ventriculoperitoneal (VP) shunt placement is a surgery performed to relieve intracranial pressure caused by hydrocephalus. A craniotomy is performed to gain access to the ventricles and draw off (shunt) cerebrospinal fluid into the peritoneal space of the abdominal cavity. VP shunt surgery is performed on patients with:

  • hydrocephalus

This information is meant to be a guide and not a substitute for veterinary care.
Always follow the instructions provided by your veterinarian.