Wobblers Syndrome in Horses

Wobbler syndrome is caused by the compression of the spinal cord, most often in the neck. This may be due to a narrow spinal canal, or malformation of the vertebrae. When compression occurs it pinches the nerves in the spine limiting the connection to the body and legs. Most often starting in the hind legs, the disconnection progresses to the whole body, and is usually symmetrical.

Wobbler syndrome is not fatal but can be dangerous for the horse, rider, and handlers. The incoordination of horses' limbs can lead to falls, injury, and trauma. With treatment it is possible to recover fully, but there are no guarantees.

Most cases are found in developing horses aged 3 months to a year, although can be found in older horses. Those horses with an already narrow spinal cord and long necks are more at risk of developing wobblers. Wobbler syndrome is common in horses, although certain breeds are more susceptible. Examples often include large, fast growing breeds such as thoroughbreds, quarter horses, warmbloods, and Tennessee walkers. It also tends to affect males 3 times more often than females due to size and growth speed differences.

An early sign of wobbler syndrome to watch for is persistent clumsiness in foals. The clumsiness of horses with wobbler syndrome can lead to related trauma and injury.

There are two different types of wobblers with unique causes.

Type 1 occurs when the vertebrae do not form properly during development, and there is a genetic factor that contributes to its occurrence.

Type 2 is arthritic and relates to trauma or stress on the joints in the neck.

The first step toward diagnosis is to determine where the symptoms originate. The only definitive diagnostic tool is a myelogram, a type of diagnostic imaging in which dye is injected into the area surrounding the spinal cord and used to determine if the spinal cord compression is static or dynamic.

Other diagnostic tests include a physical examination, and other diagnostic imaging.

Wobbler syndrome is often rated by severity and this determines the course of action.

Surgery is the only specific treatment for CVM, but not all cases are good candidates for surgery. There are two types of surgery, the first, more successful and common type is where the vertebrae are fused together, often with a piece of metal, to prevent movement from pinching the nerves. The second type is to remove bone in the spinal canal to stop the pinching.

Whether or not surgery is undergone is determined on a case to case basis by severity, lifestyle of the horse, and desired outcome.

Surgery is a very effective treatment method, and in many cases horses return to an athletic and full lifestyle, however there are no guarantees and it is costly. Full recovery takes up to a year, although improvements are often seen within 90 days.

Although surgery has proven to be a very effective treatment in most cases, horses with wobbler syndrome are not recommended for riding for the safety of the rider.

In cases where surgery is not an option, treatments such as anti-inflammatory medications, steroids, and reduced activity may be adequate for management. In more severe cases, euthanasia is the most humane alternative.

Without treatment, wobbler syndrome does not resolve on its own, and can worsen without lifestyle changes (such as reducing physical activity).

With treatment, most horses improve greatly, and many return to competing athletically, but remain a higher risk to ride for their and any rider's safety.

To prevent Type 1 wobbler syndrome it is recommended to avoid breeding any horses diagnosed with wobblers, or those with particularly narrow spinal canals. Avoiding overfeeding of young horses is also warranted.

It is important to be vigilant of any early warning signs. Vitamin E supplementation and ensuring proper nutrient balance are also among the preventative measures. Establishing baseline and pre-emptive imaging in rapidly growing foals to monitor the spinal canal and any narrowing is recommended. If narrowing of the spinal canal is observed early, measures can be taken to reduce the likelihood of wobbler syndrome. This usually consists of dietary or lifestyle changes and sometimes anti-inflammatory medication. Lifestyle changes include a short or long term hiatus from any athletic events, shows, or training, and reducing rough housing or play. It may be necessary to confine young horses during the first year and a half to accomplish this adequately. Dietary changes include reducing feed high in protein and nitrogen, as these types of feed are used for rapid growth which contributes to inadequate bone stability and density.

Wobbler syndrome, or CVM, is common in horses.

The typical treatment for wobblers is:

• Lifestyle changes
• Dietary changes
• Medication (anti-inflammatories, steroids)
• Surgery