Overview of Canine Intervertebral Disc Disease in the Thoracolumbar Area
Thoracolumbar (T-L) disc disease is a condition that occurs when pressure is placed on the spinal cord by disc material that herniates beneath or adjacent to the cord. This condition is commonly referred to as Intervertebral Disc Disease (IVDD) that can occur in the thoracolumbar area of the back. The condition may be an acute (occurs suddenly) or chronic (slowly develops over time) condition in dogs.
The exact cause of disc degeneration is unknown but in many animals there is a change in the content of the disc from a soft, pliable gel to stiff mineral. This stiff material can slowly compress the spinal cord or suddenly burst into the spinal canal. When the disc involved is in the mid-portion or thoracolumbar area of the spine (the T-L region) the front legs are not affected; they remain normal. However, the back legs may be affected to varying degrees.
If your dog develops a T-L disc herniation the signs that he shows may be mild back pain only or, in severe cases, complete paralysis of the rear legs without the ability to perceive any sensation in the limbs.
Chondrodystrophic breeds – breeds that are prone to disorders of cartilege formation such as the dachshund, Lhasa apso and Pekingese – are among the breeds more commonly affected. T-L disc disease most commonly occurs when animals are between three and seven years of age.
What to Watch For
Signs of IVDD in dogs may include:
Diagnosis of IVDD in Dogs
Diagnostic tests are needed to recognize T-L disc disease and differentiate it from other diseases that may cause similar signs.
In addition to obtaining a complete medical history and performing a thorough general physical examination, your veterinarian will likely perform the following tests:
If your dog can walk normally but has back pain, your veterinarian will palpate the spine (apply gentle pressure to it) to try to localize the pain.
If your dog can walk but is clumsy, your veterinarian will check to see that only the back legs are affected and the front legs and head are normal.
If your dog cannot walk, your veterinarian will pinch the toes of the back legs to assess your dog’s awareness of pain. Your dog may pull the leg back as a reflex response (the withdrawal reflex); however, your veterinarian will want to see if your dog cries out or tries to bite, indicating that he/she feels pain in the affected limbs. Just pulling the leg back does not indicate that your dog can feel his legs.
Treatment of IVDD in Dogs
The type of appropriate treatment will depend on the severity of the clinical signs. Dogs with milder forms of the disease may be treated medically, whereas more severe cases may need surgery. Treatment for T-L disc disease may include one or more of the following:
Strict cage rest will be essential for at least four weeks when opting for medical management. This rest is essential to allow a “scar” to form over the top of the disc material; early activity may precipitate the herniation of the rest of the disc material and worsening of your dog’s condition. You should carry your dog outside several times a day to allow him to urinate and defecate, but do not allow him to run around the yard. Failure to confine a dog with disc herniation is a common reason for early recurrence.
If your dog is unable to urinate on his own, he will need help emptying his bladder. When the bladder overfills, urine dribbles out, but this results in stretching of the bladder and may make your dog unable to urinate even if there is improvement in the condition of the spinal cord. Bladder emptying is usually done three to four times a day. If your dog is released from the hospital while he is still having difficulty urinating be sure that your veterinarian shows you how to empty the bladder (called “expressing” the bladder).
If your dog is unable to walk, physical therapy is important to promote muscle strength. Have your veterinarian or the veterinary staff show you how to do this.
Be prepared for small increments of improvement. Depending on the severity of the disease your veterinarian will estimate how long your dog’s recovery may take. Most likely your dog won’t walk immediately away after surgery. Just as in people, it takes time to recover from spinal cord injury, so be patient.
Observe your dog closely for any worsening of clinical signs. If you notice any deterioration in your dog’s condition, contact your veterinarian immediately. If he is predisposed to back problems be aware of the early signs of disc disease. If he shows any sign that might indicate a neurologic problem, seek veterinary advice as soon as possible.
Don’t let your dog become overweight. Obesity increases stress to the mid-portion of the spine of these “long dogs.”