Veterinary Care In-Depth
Veterinary care should include diagnostic tests and subsequent treatment recommendations. A neurological examination. This consists of a series of tests which help define the location of the spinal cord damage.
Diagnostic tests are needed to recognize T-L disease and differentiate it from other diseases that might cause similar signs.
In addition to obtaining a detailed history, your veterinarian will perform a general physical examination, usually taking into consideration your dog's possible back pain. Depending on the findings, other tests that your veterinarian may wish to perform include:
The head, neck and front legs are assessed to determine whether the spinal cord in front of the third thoracic vertebrae (T3) is normal or not. With T-L disc disease only the rear limbs should be affected.
The back legs may be assessed for the ability to move and walk – the presence of motor function and the ability to respond to the brain's command to walk. Your dog may be assessed as normal, clumsy or unable to walk. The tail may be held at the base to assist in this activity. The feet may then be turned over or "knuckled" to assess your dog's ability to recognize the abnormal position of the paw. Loss of the ability to recognize how the feet are placed (proprioception) indicates mild damage to the spinal cord and often precedes the loss of motor function (or the ability to move the legs). Other tests may follow to evaluate the brain's awareness of the position of the feet.
If your dog cannot walk even with support your veterinarian will pinch the toes of the back legs to assess for deep pain sensation. This is done either with fingers or with an instrument such as a hemostat. Although this may appear barbaric, it is an important test to help define the severity of the spinal cord injury. If your dog feels the stimulus, he or she should cry out or try to turn around and bite. In some dogs, subtle signs such as pupil dilation may indicate that they feel the pinch.
If your dog does not show any indication of feeling pain from this procedure, typically severe damage to the spinal cord has occurred. It is important to note that pulling the leg away when the toe is pinched does not mean that your dog feels the pain. This is just the "withdrawal reflex," not conscious sensation of pain. Crying or biting suggests that the information from the toe being pinched got past the damaged region and was received by the brain; pulling away does not.
Other reflexes are tested on the back legs to better define the location of the injury.
Your veterinarian may feel for your dog's bladder and check the muscle tone in the anal region. These sites could be affected by spinal cord injury.
Palpation, which is a technique of examining organs or body parts by touching and feeling, along the spine may reveal the most sensitive, affected area.
At the end of the examination your veterinarian will likely be able to define the location of your dog's injury, determine the severity of the problem, and make recommendations about how it should be treated. Obviously, the more marked the damage to the spinal cord, the more severe the effects on the back legs and the worse the prognosis. Additionally, the longer the damage has been present, the worse the prognosis.
Blood tests are usually not specific for this disease.
Plain radiographs (X-rays) may be helpful but are not definitive for a disc compressing the spinal cord. A myelogram – an X-ray study in which dye is injected into the spinal canal – is needed to show that the cord is swollen or pinched or buckled. Alternatively, a CT scan may be used. Myleography and CT scans require general anesthesia and are usually performed prior to surgery so that anesthesia is administered only once.
The choice of medical versus surgical treatment depends on the severity of the problem. Medical treatment
For dogs that can walk but that have back pain or are clumsy, medical treatment may be appropriate. This involves strict cage rest and the use of medications such as muscle relaxants and steroids. Your dog may be hospitalized and given a course of intravenous steroids or a course of oral steroids that taper off over a number of weeks when your dog goes home.
The common steroid used is prednisone. Administration of prednisone will likely result in your dog having an increased thirst, urinating more often, and having an increased appetite.
When the animal is unable to walk normally, is paralyzed or has no deep pain sensation, surgery may be recommended. A myelogram or CT scan may be performed to locate the exact disc space affected. The disc may have erupted on the right or left side or from directly below the spinal cord and this will affect the type of surgery performed. Usually a small window of bone is drilled in the spinal bone (laminectomy) to allow decompression of the spinal cord and access to the ruptured disc material.
Your dog will not be cured instantly by surgery. The procedure takes the pressure off the cord, allowing it the opportunity to heal. The surgery does not do anything directly to the cord itself, which must heal on its own. The chance that this can occur varies with the severity and duration of the injury.
Medical management is successful in about 80 to 90 percent of dogs with just back pain.
If your dog could still walk before surgery, but was wobbly, the prognosis following surgery is excellent.
If your dog had lost the ability to walk, but still had deep pain sensation, the prognosis following surgery is good.
If your dog had lost deep pain sensation, the prognosis following surgery becomes guarded. If this had been the case for greater than 48 hours, then the outlook for walking again is grave, whether surgery is performed or not.
Following surgery, dogs are usually hospitalized for several days to assess their early improvement and to determine the level of bladder function.
Many dogs need help emptying their bladders for awhile after surgery. Generally expressing the bladder is done three to four times a day until control over the bladder returns, and your veterinarian will show you how to perform the procedure. Medication may be used to help with bladder function.
Check the incision daily for swelling, redness or discharge. Stitches or staples are usually removed in two weeks.
Most dogs have control of their bowel movements but are unable to stand to defecate, and therefore have a tendency to soil themselves. If you can, support your dog to encourage a more normal bowel movement, and make sure the hind limbs and rump area stay clean.
After the stitches have been removed swimming in the bath can be an excellent form of physiotherapy. Passive range of motion should be encouraged in all dogs. This involves hip and knee flexion and extension exercises. This promotes good muscle tone and joint mobility in order to offset muscle wasting.
For dogs that are unable to walk, soft padded bedding will be very important. Turning your dog from side to side often, at least four times a day can help prevent the development of pressure sores.
Following spinal surgery all dogs need rest and confinement for a period of four to six weeks, even if they appear to be moving well. This allows the tissue around the surgical site to heal.
Recovery time is extremely variable. Some dogs that have been completely paralyzed may walk within a few days, and others may take several months. Some dogs may return to normal completely, while others may have residual neurological deficits. These deficits may be mild and not affect the quality of your dog's life, while others may be so significant that an owner may be forced to consider using a paraparetic cart to restore some type of mobility. Others may be forced to opt for euthanasia, when they realize that an acceptable quality of life for their dog cannot be restored.
An early diagnosis of disc disease is very important to optimize your dog's outcome. Have your dog evaluated for suspected disc disease in an emergency because progression from weakness to paralysis can occur within hours. Your veterinarian may refer you to a surgical or neurological specialist for treatment.
Avoid excessive weight gain in chondrodystrophic breeds of dogs that will result in excessive load across the thoracolumbar region of the spine.
It is uncommon for a dog that has had spinal surgery to have a recurrence at the same or another site at a later date, but if you suspect that this has happened see your veterinarian as soon as possible.