Overview of Canine Fibrocartilaginous Embolization
Fibrocartilaginous embolic myelopathy, commonly referred to fibrocartilaginous embolization and abbreviated as FCE, is a condition involving necrosis (cell death) of a region of the spinal cord secondary to infarction (obstruction) of the blood supply. The infarction is caused by fibrocartilage, which arises from part of the intervertebral disc (the shock absorbing material located between bones in the spinal column) and enters a spinal artery or vein.
The cause of FCE is unknown. It is also unclear as to how the fibrocartilaginous material enters the bloodstream. Giant and large breed dogs are most commonly affected. It may also occur in smaller dogs, with an apparent predisposition in Shetland sheepdogs and miniature schnauzers. Most affected animals are 3-6 years of age and male dogs are slightly more prone to FCE than females.
Although FCE has been reported in cats, the condition is very rare.
What to Watch For
Signs of Fibrocartilaginous Embolic Myelopathy (FCE) in dogs may include:
Lack of coordination
Dragging of limbs
Complete inability to walk
Sudden onset of weakness or paralysis in one, several or all limbs
Diagnosis of Fibrocartilaginous Embolic Myelopathy (FCE) in Dogs
History and physical exam
Spinal radiographs (X-rays)
Myelography (specialized X-ray using agents to highlight the spinal cord)
Cerebrospinal fluid (CSF) analysis
Complete blood count, biochemical profile and urinalysis
Treatment of Fibrocartilaginous Embolic Myelopathy (FCE) in Dogs
Intravenous corticosteroid therapy may be useful if administered within 6-8 hours of onset of clinical signs in dogs. Additional treatment includes:
Home Care and Prevention
Recovery may be a slow process, requiring continued supportive medical care at home. Some affected animals may lose the ability to urinate normally. This may necessitate manual emptying of the bladder and frequent cleaning of the hind end to avoid urine scalding.
Pressure sores are a common complication of prolonged paralysis. Frequent turning of paralyzed animals, soft bedding, and management of any sores is also necessary.
There are no known measures to prevent FCE.
In-depth Information on Fibrocartilaginous Embolization in Dogs
FCE is a disease most commonly seen in large dogs. The onset of clinical signs often occurs following exercise or some form of mild trauma. It is generally considered to be a non-painful condition, although owners often report apparent pain or vocalization when the signs first occur.
The onset of signs is very acute (sudden). The type of problems seen depend on which part of the spinal cord is involved. If the infarcted portion of spinal cord is in the neck, both front and hind legs may show abnormalities. If the infarcted portion of spinal cord is behind the front legs, there may only be a problem with the hind legs. Additionally, the signs are usually asymmetric, meaning they are worse on one side of the body than the other.
The degree of neurologic deficit may range from a mild lameness to complete paralysis of one or more legs. There may be some worsening of signs over the first 12-24 hours, but the deficits do not progress beyond this time period. Other diseases that may cause signs similar to FCE include:
Vertebral fracture (or other spinal trauma). Fracture of one of the vertebrae may result in compression of the spinal cord with resulting limb weakness or paralysis. Fractures of this nature are usually sustained following major trauma (such as being hit by a car) and the animal would be expected to exhibit continuous pain. Neurologic deficits are most often symmetric in this instance.
Intervertebral disc disease. Rupture or herniation of one of the discs that sit between the vertebrae (“slipped disc”) can cause a sudden onset of paralysis similar to FCE. Animals suffering from this condition are very painful and tend to have more symmetric signs as well. Acute rupture of intervertebral discs is also more common in small dogs, whereas FCE is more common in large dogs.
Diskospondylitis. This is an infection of the intervertebral disc. This is yet another painful disease process and the animals often show other signs of illness such as fever and lethargy. Depending on the severity of the infection, the animal may or may not have neurologic deficits.
Spinal tumor. Cancer of the spinal cord or of the vertebrae may produce a non-painful and asymmetric weakness or paralysis of the limbs, but this usually follows a gradual course, with slowly progressive signs.
Myelitis. Myelitis is an inflammatory condition of the spinal cord. This also generally has a slower onset of signs and is a progressive disorder.
Spinal cord hemorrhage. Certain bleeding disorders may cause hemorrhage in and around the spinal cord, which may also interrupt normal neurologic function. Most animals with bleeding disorders show evidence of bleeding elsewhere in the body rather than strictly associated with the spinal cord.
In-depth Information on Diagnosis of FCE in Dogs
A thorough history and physical exam are imperative to making an appropriate diagnosis. Detailed information about the onset and progression or lack of progression of clinical signs, as well as the possibility of trauma may be useful in developing an accurate list of potential diagnoses. A careful neurologic exam will localize the area of the spinal cord that is abnormal, as well as assess the degree of neurologic compromise. Assessment of mobility as well as the animal’s ability to feel a stimulus applied to the limbs also helps determine the prognosis for recovery. More specific tests include:
Spinal radiographs. Radiographs (X-rays) are an important part of the diagnostic work-up as they will help rule out fractures, bone tumors, diskospondylitis and possibly disc herniations. Most cases of FCE have completely normal radiographs.
Myelography. A myelogram is a special type of X-ray that uses a contrast agent (dye) to outline the spinal cord. This contrast demonstrates if the spinal cord is compressed at any point along its path, or if there is a mass (tumor) associated with the spinal cord. This test is very useful in ruling out the other aforementioned disease processes. Many cases of FCE have a normal myelogram. Occasionally there is mild spinal cord swelling associated with the infarct which may alter the appearance of the study, but this occurs early and does not persist. Evidence of significant spinal cord compression is not consistent with a diagnosis of FCE.
CSF analysis. The cerebrospinal fluid of animals with FCE is usually normal, but may have some evidence of hemorrhage or elevated protein levels. Evaluation of CSF cannot provide a diagnosis of FCE but it can be useful in diagnosing other processes such as certain cancers and inflammatory spinal cord diseases (myelitis).
Complete blood count (CBC), biochemical profile and urinalysis. These tests are a routine component of many diagnostic work-ups. The CBC provides information with respect to the red and white blood cells and the platelets. The biochemical profile provides important information with respect to liver and kidney function, as well as electrolyte levels and the urinalysis provides more information with respect to kidney function. These tests are expected to be normal in patients with FCE, but they help rule out other disease processes, and provide a more complete picture of the patient’s overall health.
In-depth Information on Therapy of FCE in Dogs
The mainstay of therapy for FCE is supportive care. FCE cannot be definitively diagnosed in a living patient, therefore all other diseases that may present with similar clinical signs must be ruled out using the aforementioned diagnostic tests. There is no surgical procedure to repair the infarcted portion of the spinal cord, so healing must occur on its own. Some treatments may include:
If the patient is presented to the hospital within 6-8 hours of the onset of clinical signs, intravenous treatment with corticosteroids may limit the degree of damage that occurs to the spinal cord. Beyond this early stage, steroid therapy is not indicated for FCE.
Supportive care is crucial for animals that are immobilized by spinal cord disease. Since many animals with FCE are large breed dogs, caring for them during the recovery phase can be challenging. Patients must be able to maintain an upright position to eat and drink. In some cases they may need physical support to stay in an appropriate position. Additionally, if they are lying on one side, they need to be rotated several times a day so that alternate sides of the body are facing up.
Physical therapy on the limbs is important to help maintain good muscle tone.
Attention must be paid to whether the patient is able to urinate normally. Depending on what part of the spinal cord is involved, some animals may either lose the ability to empty their bladder, or may develop urinary incontinence. Manual bladder expression may be required in the former case and frequent cleansing of urine soaked hair and skin may be necessary in the latter case. If urine retention is a problem, animals become prone to urinary tract infection. Foul smelling or discolored urine should be analyzed for the presence of infection. Antibiotics are indicated if infection is documented.
Monitoring for the development of pressure sores should also be performed.
Follow-up Care for Dogs with Fibrocartilaginous Embolization
Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your dog does not rapidly improve.
Many dogs will recover from FCE, but it can be a slow process. The patient should be evaluated by your veterinarian 10-14 days after discharge from the hospital and approximately once a week thereafter, until marked improvement is noted.
Many animals will start to show signs of improvement in the first 7-10 days. If there is no improvement within three weeks, the prognosis is guarded.
Regularly scheduled re-exams are important for full neurologic evaluation. Subtle changes in your dog’s status may go unnoticed until a full exam is performed.
Supportive care started in the hospital must be continued at home. If your dog appears to be getting worse, this should be brought to your veterinarian’s attention immediately.