Dog - Back Problems (Cauda Equina)

Back problems in dogs are not uncommon and can be due to a variety of causes ranging from intervertebral disc problems such as occur with us (slipped disc), trauma due to a fall or road accident, or infection involving the spinal discs, the bone of the spine or sometimes the nerve tissue itself. All these diseases are extremely painful and affect the dog’s motility.

Just like us, spinal pain can affect any area of the dog’s spine, from the neck to the pelvis. Most commonly dogs are affected with lower back pain, known scientifically as cauda equina syndrome or lumbar sacral syndrome. This defines the area where the lumbar spine ends and the sacrum, which is part of the pelvis, commences. This area is where the spinal cord divides into a number of major nerves. These control movements of the hind legs and tail and also help to control passage of faeces and urine.

The syndrome covers a collection of diseases that can occur when these nerves become compressed or trapped. This causes pain, paralysis, faecal and/or urinary incontinence or, in some cases, hind leg lameness which is similar to sciatica. The most common cause of the nerve pressure in dogs is lumbar sacral stenosis, a narrowed spinal canal. This is a condition which is most often seen in large breed dogs such as the German Shepherd.

Other causes affecting a wide variety of breeds and sizes of dogs include infection of the intervertebral disc, injury, a spinal tumour or instability of the joint.

What are the clinical signs?

Pressure on the spinal cord of the emerging nerves causes inflammation which can also affect the muscles in the immediate area. Affected dogs are in pain and often a first sign is crying out when attempting to jump into a car or negotiating steps or stairs. Pressure on the muscles of the lower back is often resented. Others signs can be faecal or urinary incontinence. Some dogs mutilate their hindfeet or tail with constant chewing.

The disc at the site may rupture and if this happens the dog will become even more incoordinated or may suddenly develop posterior (back end) paralysis.

How is it diagnosed?

Diseases such as hip dysplasia and arthritis can result in similar signs, therefore careful diagnosis is essential. Radiography (x-ray) will generally reveal arthritic changes at the lumbosacral junction particularly in larger or working breeds of dogs. This may not be the cause of the clinical signs. Sometimes even a plan radiograph will show evidence of a narrowed disc space. If the clinical signs fit and the initial radiographs are suggestive of lumbosacral problems, specialised diagnostic techniques involving myelography will highlight any areas of pressure on subsequent radiographs. Myleography is a technique where special dye is injected around the spinal cord so that the cord (and any compression of it) can be seen on an xray. CT or MRI scans may sometimes be necessary to arrive at a positive diagnosis.

What is the treatment?

Initially if your dog is overweight, weight reduction is essential and we will be happy to advise.

Strict rest is also an important part of treatment for any back problem. Cage rest may be necessary but we will discuss this fully with you.

Anti-inflammatory drugs together with pain control via NSAIDs (non-steroidal anti-inflammatory drugs) will often give relief.

Discospondylitis (infection of the intravertebral disc) is not a common cause but does occur and can be treated with appropriate antibiotics. Treatment is usually fairly prolonged, requiring 6–8 weeks of treatment. If the disc ruptures, as mentioned many dogs will at best become uncoordinated or even paralysed. Surgery is then indicated. The procedure, a dorsal laminectomy, relieves the pressure of the bulging or ruptured disc material on the spinal cord. It also permits identification of any spinal tumour or narrowing of the spinal canal due to injury. Provided there is no irreparable damage to the spinal cord progress following surgery is usually good although sometimes return of function can take months rather than weeks during which medication in the form of pain relief and anti inflammatory drugs may have to be continued.

Please feel free to contact us if you wish to discuss any problems.