Brain Tumor Removal
Cats and dogs can develop brain tumors just as people do. Clinical signs can vary from altered behavior to uncontrollable seizures. Often times, brain tumors in cats occur at a superficial location making resection of the tumor feasible. Although the surgery is elaborate and delicate, cats with a relatively small mass in a superficial location are likely to make an uneventful recovery from surgery. Dogs, unfortunately, generally develop brain tumors in inaccessible locations such as the floor of the brain making conventional surgery next to impossible.

Intervertebral Disc Disease
An intervertebral disc is a shock-absorbing cushion between the bones of the vertebral column. The center of the disc is composed of a gelatinous substance called the nucleus pulposus and imparts the shock absorbing properties of the disc. The outer fibrous layer of the disc called the annulus fibrosis and imparts the strength characteristics of the disc. Clinical signs of intervertebral disc disease occur when the disc ruptures or herniates to cause compression of the spinal cord or nerve roots. Clinical signs begin with signs of back pain and may progress to incoordination, weakness, and the inability to support weight, loss of pain sensation and finally complete paralysis. The progression of signs is dependent upon on the degree of compression and the rate at which the compression has occurred. The loss of voluntary movement and pain sensation are serious signs that require immediate attention if hope for return to function is to be expected. 

There are two types of disc diseases: Type I and Type II disc herniations. Chondrodystrophic dogs (Dachshunds, Pekinese, Lhasa Apso, Shi Tzu, Beagles, etc) are commonly affected by Type I disc ruptures. Overtime these patients develop chondroid degeneration of the intervertebral disc. This degeneration results in loss of water within the nucleus pulposus of the disc and a loss of the shock absorbing properties of the disc. This leads to a rapid rupture of the disc and compression of the spinal cord. Signs may begin acute and progress rapidly over 12-24 hours. Non-chondrodystrophic dogs are affected by Type II disc herniations. This disease process is characterized by fibroid degeneration of the outer annulus layer of the disc. This can lead to a bulging of the annulus and a slow onset of compression of the spinal cord.

Diagnosis of the condition involves a careful neurologic evaluation to localize the area of the spinal cord that is injured. Imaging studies such as a MRI evaluation of the spinal cord or a myelogram are required to confirm to presence and location of compression. 

There are two categories of treatment: medical management and surgical decompression of the spinal cord. 

Medical management of intervertebral disc disease can be considered for patients with an initial episode of pain with minimal or no neurologic deficits present. The goal of medical management is to maintain a good level of comfort and restrict the patients activity to cage rest. 

Surgical decompression of the spinal cord should be considered when initial signs are more severe, such as moderate to severe neurologic deficits. Paralysis with loss of pain perception is a surgical emergency. Rapid intervention in cases with loss of deep pain can offer a potential for return to acceptable function. Surgical intervention can also be considered for recurrent episodes of pain or mild paresis that is not responsive to medical management. Surgical decompression involves creating a window in the bony spinal column exposing the compressive disc material and spinal cord. The disc material is carefully removed through the bone window. A procedure called disc fenestration may also be performed to reduce the likeliness of additional disc herniations later in life. 

The prognosis for recovery to acceptable function depends on the degree of spinal cord injury. Unfortunately, there is no test that can determine if a spinal cord injury is a permanent injury or a reversible injury. Dogs that have maintained deep pain prior to surgery have a recovery rate of 80-90%. Dogs that have lost deep pain and have surgical intervention within 12 hours of the onset of signs have a recovery rate of 50-60%. The recovery rate drops precipitously to 25% as the duration of compression increases to 12-36 hours. Beyond 36 hours, the recovery rate is less than 5%. Regardless of presenting signs, patients that experience significant improvement during the first two weeks following surgery are likely to make a complete recovery. For example, if a patient has lost pain perception prior to surgery and has return of pain perception at the time of suture removal, 90% will go on to make a complete recovery. 

During the recovery period, patience, providing a clean, dry, well-padded environment and physical therapy are critical.