Wobbler’s Syndrome is caused by a narrowing of the vertebral canal in the neck, which causes compression of the spinal cord. The spinal cord carries nerve signals that coordinate movement to the horse’s limbs. Compression of the spinal cord, therefore, disrupts these signals, resulting in weakness, loss of coordination, and abnormal limb positioning.
The Syndrome typically affects young, fast-growing horses, with clinical signs often present between six months and three years of age. However, older horses can sometimes be affected.
Clinical signs of the disease include:
- Weakness
- Incoordination
- Toe dragging
- Stumbling
- A wide-based stance
- Abnormal standing limb position
- Stiff neck
Diagnosis
Diagnosis typically involves:
- Taking a history and performing a basic neurological examination. A pretty convincing diagnosis can often be reached based on the horse’s history and the neurological examination results.
- Taking multiple X-Rays. X-Rays of the neck are then taken to aid diagnosis. Areas of abnormal bone development that result in spinal compression might be seen on the X-Ray. In some cases of Wobbler’s Syndrome, however, the issue is more dynamic, where there is no compression of the spinal cord when the neck is in a relaxed position, but that when it is flexed, the cord in the neck becomes compressed. These dynamic cases are typically much more challenging to identify and diagnose.
- CT. A CT is effectively a 3D X-Ray, which allows the vertebral canal to be studied in more detail. A general anaesthetic may be required for some horses to tolerate a CT, and even with an anaesthetized horse some of the more critical neck joints are difficult to visualise correctly.
- Myelography. This technique involves the injection of a contrast solution into the vertebral canal (where the spinal cord runs). The horse then has a CT scan or X-Rays taken to assess the dispersal of the contrast. The contrast surrounds the spinal cord and makes any areas of compression more obvious.
Treatment
There are a few treatment options that your vet might suggest, including:
- Anti-inflammatories. These help to reduce the soft tissue swelling around the spinal cord and thus reduce the compression.
- Medicating the neck joints to help reduce compression of the spinal column can help in horses with mild clinical signs.
- Reducing protein and carbohydrate intake in young, fast-growing horses can help to slow growth and limit the progress of the disease.
- Surgery can be attempted to stabilize the affected neck joints. However, this invasive option is only very rarely undertaken.