Cauda Equina Syndrome in Dogs

Similar to the back pain that humans commonly have, cauda equina syndrome is usually a slowly progressing disease as the calcification of the spine increases with age. You may not even notice that your dog is having problems with his back even after some of the symptoms start because they can seem unrelated. For example, incontinence is not usually suspected to be a back problem on its own; it is commonly considered to be a behavioral problem without other symptoms. However, if you have a large breed dog such as a German Shepherd or a dog with a long spinal cord like the beagle, you may want to have it checked out by a veterinary professional; especially if your dog has been housetrained for a long time and then suddenly starts having accidents in the house.

Cauda equina syndrome (lumbosacral stenosis) is a severe and painful progressive arthritis in the joint at the bottom of the spine. The spinal canal gets narrower as the arthritis gets worse and compresses the nerves in that area, making it extremely painful for your dog to walk or wag his tail. Also, the disc between the sacrum and the vertebra is usually deformed, which causes more compression on the nerves. Once the nerves are completely compressed, your dog will not be able to use his back legs or control his bladder or bowel movements.

The symptoms of cauda equina syndrome usually do not begin until your dog is three to seven years old. The sign that is most evident is pain in the rear legs, tail, and the back. Other common signs of this debilitating disease include:

• Difficulty getting up
• Poor coordination
• Posture changes
• Not able to climb stairs
• Weak rear legs with muscle loss
• Trouble urinating or defecating (sometimes causing incontinence)
• Dragging rear paws
• Unable or unwilling to move tail because of the pain
• Shuffling and scuffing toes
• Chewing on rear legs and tail (possibly causing a lot of damage)

Types

• Congenital cauda equina syndrome is a disease your dog is born with
• Acquired cauda equina syndrome is caused by something such as injury, infection, or tumor

• Large breeds (German Shepherd, Great Danes) and dogs with long spinal cords (Beagle, Dachshund) are most susceptible
• Infected disc
• Injury
• Tumor
• Joint instability
• Congenital lesions of the vertebrae
• Inflammatory disease such as neuritis
• Metastatic neoplasia such as prostatic carcinoma
• Primary neoplasia
• Subluxation or luxation
• Fractures
• Herniated disc
• Acute intervertebral disk extrusion

This condition is often hard to diagnose because the symptoms resemble so many other conditions such as hip dysplasia, prostate disease, spinal tumors, and infections. Even with a thorough physical examination, the veterinarian will likely only be able to give a possible cause so laboratory tests and imaging are essential to a definitive diagnosis. On physical examination, the veterinarian will likely find that your dog has pain in the lower back, tail, and hind legs. However, as stated before, this is common in many conditions.

To get a positive answer, the veterinarian will use radiographs (x-rays), which will probably reveal spinal degeneration. As this is common in other conditions as well, an epidurogram and a myelogram are the best courses of action. Both use a contrast dye in conjunction with radiographs (epidurogram) and CT scans (myelogram) to get a detailed view of the spinal cord.

There are various types of treatments for dogs with cauda equina syndrome including both surgical and nonsurgical options. Medication to relieve the pain is prescribed; cage rest usually accompanies this treatment. However, the condition is progressive so further treatment is usually necessary.

Nonsurgical Treatment

With mild cases of cauda equina syndrome, corticosteroids or NSAIDs for inflammation and pain will usually be tried first. A cortisone injection is sometimes given for immediate relief. Cage rest for one to two months is also suggested but you have to be sure to keep working with your dog daily to keep the muscles from atrophying (weakening). Often, as the condition worsens, the pain will return and further treatment will be required.  

Surgical Treatment

There are a couple of surgical options used for cauda equina syndrome, which include decompression and fusion. Decompression (laminectomy) is the removal of the degenerated disc. To do this, an incision in the top of the spinal cord is used to remove the bone and sometimes the ligaments along with other material pressing on the nerves. Fusion is done to strengthen the spinal cord and to stop the compression of the nerves. This is done by using bone from another part of the body, a bone bank, or a metal plate, depending on the circumstances.

Although this is a serious and debilitating condition, with treatment your dog should be able to live a long and happy life. If the condition was mild and your dog is put on medication and rest, he may be able to go several more years before needing surgery. With surgery, your dog will have to be on cage rest for a while longer, but the end result is that your dog will be back to his old happy self. Obesity causes stress and pressure on the spine, so be sure to watch his diet and make sure he gets plenty of exercise.