Cervical Spondylomyelopathy (Wobbler Syndrome) in Dogs
TL;DR. Cervical spondylomyelopathy (Wobbler Syndrome) is a progressive neurological condition in large and giant breed dogs where spinal cord compression in the neck causes a characteristic uncoordinated, wobbly walk.
Wobbler Syndrome primarily affects large and giant breed dogs, causing coordination issues that often start in the hind limbs.
What is it?
Cervical spondylomyelopathy (CSM), widely known as Wobbler Syndrome, is a degenerative condition of the spine in large and giant breed dogs. The term "spondylomyelopathy" refers to a disease that simultaneously affects the vertebrae (the bones of the spine) and the spinal cord. In dogs with CSM, the spinal cord and the delicate nerve roots in the neck (caudal cervical spine) become compressed.
This compression occurs due to a combination of developmental malformations of the vertebrae, instability of the spinal column, or changes associated with that instability, such as bulging intervertebral disks or thickened ligaments. The spinal cord acts as the primary highway for communication between the brain and the rest of the body. When this highway is squeezed, the neurological signals traveling to the limbs are disrupted.
For owners, this disruption is most visible as a loss of coordination. Because the hind limbs are furthest from the brain, they are typically affected first and most severely, giving the dog a characteristic "wobbly" or uncoordinated gait. Understanding this condition is crucial for owners of predisposed breeds, as early intervention can significantly impact your dog's comfort and long-term mobility.
Causes & risk factors
Cervical spondylomyelopathy is primarily a developmental and degenerative disease. While the exact underlying trigger can vary, the compression is generally caused by one of two primary mechanisms: bony malformations of the spinal canal or disk-associated compression.
In younger giant-breed dogs, the condition is often linked to developmental malformations of the vertebrae themselves. These malformations can cause the spinal canal to be abnormally narrow, or they can lead to instability where the vertebrae shift and pinch the spinal cord.
In mature large-breed dogs, the condition is more commonly associated with Disk-Associated Wobbler Syndrome (DAWS). In these cases, chronic instability between the vertebrae leads to bulging or herniation of the intervertebral disks, which then press upward against the bottom of the spinal cord.
Genetics and body conformation play a massive role in this disease. It is almost exclusively seen in large and giant dog breeds. Rapid growth rates and specific skeletal structures are suspected to contribute to the development of the vertebral abnormalities that trigger the condition.
Signs to watch for
The signs of cervical spondylomyelopathy usually develop slowly and progressively, though they can occasionally appear suddenly if a dog experiences a minor trauma or an acute disk herniation.
Cardinal Sign
- Uncoordinated or wobbling gait (Ataxia): This is the hallmark sign of the disease. The dog may appear clumsy, sway in the rear end, or walk as if they are intoxicated.
Common Signs
- Ataxia: General lack of coordination in the limbs.
- Paresis: Weakness in the limbs, particularly the hind legs.
- Proprioceptive deficits: The dog may "knuckle" (walk on the tops of their paws) or stand with their paws in abnormal positions because they cannot fully sense where their feet are in relation to the ground.
- Broad-based rear limb stance: Standing with the hind legs spaced abnormally far apart to maintain balance.
- Resistance to dorsal extension of the neck: Your dog may resist or show discomfort when their head is gently tilted upward.
- Abnormal postural reactions in the rear limbs: Slower-than-normal correction when a vet tests their paw placement.
Occasional Signs
- Hyperreflexia in the rear limbs: Overactive reflexes when the hind limbs are tapped.
- Floating or overreaching front limb gait (Hypermetria): The front legs may lift abnormally high, looking almost like they are marching.
- Short-strided, weak front limb gait: The dog may take tiny, choppy steps with their front legs while their back legs take long, sweeping strides.
- Weak withdrawal reflex: A reduced ability to pull the paw away when pinched.
- Pronounced muscle atrophy: Visible wasting of the shoulder muscles (supraspinatus and infraspinatus) or muscle loss in a single front limb.
- Root signature: Pain or lameness in a front limb caused by compression of a specific nerve root; the dog may hold the leg up or cry out when the limb is gently pulled.
- Overt cervical pain: While neck stiffness is common, actual crying out or severe neck pain is the primary complaint in less than 10% of cases.
- Sudden tetraplegia: Complete paralysis of all four limbs, which can happen suddenly after a fall or acute disk rupture.
A broad-based rear limb stance is a common compensatory sign of spinal cord compression in affected dogs.
How vets diagnose it
Diagnosing Wobbler Syndrome begins with a thorough physical and neurological examination. Your vet will watch your dog walk, test their reflexes, and assess their conscious proprioception (their awareness of where their limbs are). They will also gently manipulate the neck to check for stiffness or resistance.
To pinpoint the cause of the coordination issues, your vet will need advanced imaging.
- Survey Radiographs (X-rays): While standard X-rays cannot show the spinal cord itself, they are useful for ruling out other bone diseases, fractures, or obvious vertebral malformations. They can also show narrowing of the disk spaces.
- Myelography: This is an older imaging technique where a contrast dye is injected into the space surrounding the spinal cord before taking X-rays. It helps highlight where the spinal cord is being squeezed, though it has largely been replaced by safer, more advanced imaging.
- Magnetic Resonance Imaging (MRI): This is the gold standard for diagnosing cervical spondylomyelopathy. An MRI provides highly detailed images of both the bones and the soft tissues, including the spinal cord and intervertebral disks. It allows the vet to see exactly where and how severely the spinal cord is compressed.
As noted in a leading veterinary internal medicine reference:
"MRI also allows detection of signal changes within the spinal cord parenchyma that may be associated with prognosis for recovery."
Treatment options
Treatment for Wobbler Syndrome falls into two main categories: medical management and surgical intervention. The choice depends on the severity of the spinal cord compression, the dog's age, and how long the symptoms have been present.
Medical Management
Medical management is typically reserved for dogs with mild or minimal neurological signs, or for cases where surgery is not an option due to age, concurrent health issues, or financial constraints.
- Corticosteroids (Glucocorticoids): These are the first-line medical therapy. They are powerful anti-inflammatory medications used to reduce swelling and inflammation around the compressed spinal cord.
- Strict Activity Restriction: Dogs undergoing medical management must be kept quiet. This means no running, jumping, or rough play. Walks should be short, controlled, and strictly on a leash.
- Harness Use: You must never use a neck collar on a dog with Wobbler Syndrome. All leash pressure must be redirected to a chest harness to avoid putting any extra stress on the unstable neck vertebrae.
Surgical Management
For dogs with moderate to severe neurological deficits, or those who do not respond to medical management, surgery is often the best path forward. The goal of surgery is to decompress the spinal cord and, if necessary, stabilize the unstable vertebrae.
There are several surgical techniques available, ranging from removing the bone or disk material pressing on the spinal cord (decompression) to placing implants to fuse the unstable vertebrae together (stabilization). Your veterinary surgeon will recommend the best technique based on your dog's specific MRI findings.
Postoperative care is intensive. As a leading internal medicine reference states:
"Strict postoperative confinement is important for 4 to 8 weeks, followed by a gradual return to exercise and work."
Magnetic Resonance Imaging (MRI) is the gold standard for diagnosing the exact location and severity of spinal cord compression.
Prognosis
The prognosis for dogs with Wobbler Syndrome varies depending on the severity of their symptoms and the treatment path chosen.
If left entirely untreated, the clinical course of Wobbler Syndrome is typically chronically progressive, meaning the dog's coordination and strength will continue to deteriorate over time. However, in up to 25% of mildly affected dogs, the signs may remain stable for long periods without worsening.
- With Medical Management: Medical therapy can be effective long-term in 40% to 50% of dogs with minimal or mild signs, helping them maintain a comfortable quality of life.
- With Surgical Management: Surgery leads to a successful outcome (stabilization or improvement of symptoms) in about 80% of cases. However, it is important to note that surgery does not alter the long-term survival rate, as degenerative changes can eventually develop in other parts of the spine.
According to a leading veterinary internal medicine reference:
"The prognosis is excellent for resolution of lameness and mild neurologic deficits. Most dogs with mild to moderate deficits will return to working function. Dogs with severe LMN deficits or incontinence are likely to have permanent deficits."
Prevention
Because cervical spondylomyelopathy is primarily a developmental and genetic condition, there is no guaranteed way to prevent it. However, there are steps you can take to minimize the risk and protect predisposed dogs:
- Responsible Breeding: Dogs diagnosed with CSM or those known to have produced affected offspring should not be bred.
- Controlled Growth: For giant-breed puppies, work closely with your vet to ensure they are on a diet formulated specifically for large breeds. This helps prevent rapid, uneven bone growth that can contribute to vertebral malformations.
- Use a Harness Early: If you own a breed highly predisposed to Wobbler Syndrome, transition them to a chest harness early in life rather than relying on a traditional neck collar. This protects the cervical spine from repetitive pulling forces.
When to call your vet
You should schedule an appointment with your vet if you notice any changes in your dog's gait, such as mild slipping, swaying of the hindquarters, or a tendency to trip.
You must seek emergency veterinary care immediately if your dog:
- Suddenly loses the ability to stand or walk on any of their legs.
- Becomes completely paralyzed in all four limbs (sudden tetraplegia).
- Shows signs of extreme neck pain, such as holding their head low, crying out when moving their head, or refusing to eat from their bowl on the floor.
For specific breeds
While any large or giant breed dog can develop Wobbler Syndrome, certain breeds are highly predisposed, and the disease often manifests differently depending on the breed.
- Doberman Pinschers: Dobermans are highly susceptible to Disk-Associated Wobbler Syndrome (DAWS). This typically causes compression on the bottom (ventral) side of the spinal cord and is most commonly diagnosed in mature dogs between 6 and 8 years of age.
- Great Danes, Mastiffs, Rottweilers, and Bernese Mountain Dogs: In these giant breeds, the condition is usually developmental and bone-associated. It typically causes compression on the top or sides (dorsal or dorsolateral) of the spinal cord, and signs often become clinically evident much earlier, when the dogs are between 1 and 4 years of age.
As described in a leading veterinary textbook:
"Young large-breed dogs such as Mastiffs, Rottweilers, and Bernese Mountain Dogs with CSM most commonly experience dorsal or dorsolateral spinal cord compression that becomes clinically evident when they are between 1 and 4 years of age. Disk-associated wobbler syndrome (DAWS) causes ventral compression of the caudal cervical spinal cord in mature large breed dogs, especially 6- to 8-year-old Dobermans."
Sources
- Internal Medicine, 5th Edition, pages 1102, 1103, 1104.
