Cauda Equina Syndrome in Dogs

A dog's spine is made up of many bones and in between each there is a disc that acts as a shock absorber which in short, offers protection from trauma and shock. There are twenty-seven bones in total that make up a dog’s spine and this does not include those found in the tail. Each of the discs that separate the vertebrae is made up of a fibrous ring with the inner part being a pocket of gelatinous-like matter. Then there are ligaments as well as muscles that support a dog's vertebrae. A dog’s spinal cord is protected by the many bones and when things go wrong, it can lead to a dog suffering from a condition known as caudia equina syndrome which is when vital nerves get compressed causing all the problems.

The Causes

A dog’s spinal cord ends at their sixth lumbar vertebrae which is found in their lower back. The nerves to a dog’s back legs, tail, bladder and rectum come off this part of the spinal cord which resembles a horse's tail which is why it is known as the cauda equina. Cauda equina syndrome is caused by these nerves becoming compressed which negatively impacts a dog's back end and their back legs.

As the disorder worsens, sciatic and sacral nerves are negatively affected and this in turn can lead to dogs developing degenerative arthritis in their spines. However, dogs can also suffer other conditions as a result of the condition which includes the following:

• Congenital deformity of bones
• Acute intervertebral disc herniation
• Chronic bulging disc
• Disc infections and infection in adjacent vertebrae
• Fractures
• A partial dislocation of vertebrae
• Tumours
• Inflammation of nerves
• Infection in the spine

One of the most common forms of cauda equina syndrome seen in dogs is a condition known as degenerative lumbrosacral stenosis and it is when pathological changes occur in a dog's spine which results in nerves becoming compressed. This in turn means there is a thickening seen in a dog's intervertebral disc as well as their interarcuate ligament. It also results in a thickening of joints found in the spine which is due to arthritis setting in. However, a vet would want to rule out any other conditions that have the same or similar symptoms which includes the following health issues:

• Fibrocartilaginous Embolic Myelopathy - also known as spinal cord stroke
• Degenerative Spinal Cord Disease - also known as myelopathy
• Muscle weakening disease - also known as myopathy
• Myasthenia gravis
• Blood clot in the arteries of the hind limbs
• Hip dysplasia
• Cruciate ligament rupture
• Polyarthritis

Breeds Most Affected

The breeds that are most affected by the condition tend to be larger dogs although older dogs too are more predisposed to suffering from the condition. The breeds most at risk include the following:

• German Shepherds
• Great Danes
• Airedale Terriers
• Irish Setters
• English Springer Spaniels
• Boxers
• Labrador Retrievers
• Golden Retrievers

It's worth noting that dogs tend to show signs of there being something wrong with them when are anything from six to seven years old with male dogs being most affected by the condition.

Symptoms Associated with the Disease

Dogs start to show signs of there being something wrong with them which is typically when they are around 6 or 7 years old and the symptoms most commonly associated with the condition are as follows:

• Weakness in back legs which can be intermittent or continuous
• Lameness on one of their back legs which is caused by a bulging intervertebral disc that occurs on one side of the spine
• Pain
• A crouched stance
• An odd gait where back legs move weirdly
• Incontinence which is a symptom that occurs in the latter stages of the condition
• Difficulty passing faeces
• An inability to wag or raise their tails
• Self-mutilation of tail which is thought to be because of a tingling feeling dogs experience in their tails

Diagnosing the Condition

A vet would ideally need to have a dog's full medical history, their ancestry and be told how the onset of any worrying symptoms first presented themselves. The more information they have the better because it allows them to establish a preliminary diagnosis. The vet would thoroughly examine a dog's spine if they think they are suffering from cauda equina syndrome and would typically recommend carrying out the following tests to confirm a diagnosis:

• An electromyogram test which detects whether a dog's muscles is sending out the right signals or whether there is any nerve damage
• X-rays
• Myelogram
• Epidurogram
• CT scan
• MRI scan

If the vet suspects a dog has developed a tumour, they would recommend doing chest X-rays to make sure the tumour has not spread to a dog's lungs although if the tumours are tiny, they are often not picked up on an X-ray.

Treatment Options

Once a dog has been diagnosed as suffering from cauda equina syndrome, they would need to have their exercise restricted. The vet would typically prescribe a course of anti-inflammatories which dogs need to be given over a period of anything from four to six weeks. It is also worth bearing in mind that only around half of the dogs treated for the condition respond well to a treatment and that it depends on the severity of their condition too.

Should a dog not respond to a therapy, the vet might recommend surgery, but this depends on the severity of the dog's condition. The procedure is known as a laminectomy"" and is quite complicated with dogs having to remain hospitalised until they make a significant recovery. With this said, any dog that has developed cauda equina syndrome would need to have their condition assessed by a vet before any sort of treatment, therapy or surgery would be set in place and the prognosis tends to be guarded.

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