A fibrocartilaginous embolism (FCE) is a fairly common disorder in which a piece of fibrous cartilage obstructs the blood supply to the spinal cord. It is suspected that fibrocartilage from the soft gel-like center (the nucleus pulposus) of an intervertebral disc enters a vertebral blood vessel, blocks the vessel and causes a “stroke” to the spinal cord. When the flow of blood is reduced or stopped, that part of the spinal cord goes without oxygen and nutrients and the neurons in the spinal cord become dysfunctional and can die off, leading to the clinical signs we see.
A fibrocartilaginous embolism typically occurs during times of activity, such as running or jumping. The majority of dogs will yelp once, or seem painful at first, but later there is typically no pain associated with this disease. The usual signs are a very abrupt loss of function to one limb, both hind limbs, one side of the body, or all four limbs, depending on what part of the spinal cord is affected. Most often, one half of the body is significantly worse than the other.
With any loss of function due to a nervous system abnormality, a referral to a Veterinary Neurologist is always recommended.
A presumptive diagnosis can be made based on the history and a thorough neurological examination. With a sudden onset of neurologic weakness and absence of pain, a fibrocartilaginous embolism is the most probable diagnosis.
Certain breeds are more likely to experience this disorder. Large breed dogs and the miniature schnauzer are predisposed to developing this condition.
Spinal radiographs (X-rays) are helpful to rule out a fracture or other traumatic cause.
The best way to definitively diagnose an FCE is to perform an MRI (magnetic resonance imaging) of the part of the spinal cord affected. This will help to confirm a diagnosis and to rule out other causes of neurologic weakness.
An MRI can also help give a prognosis for the return of function based on the size of the area of “stroke.” A CT scan (computed tomography) and myelogram are other tests that can be performed to look for other causes of spinal cord dysfunction, but are less sensitive for confirming an FCE.
There is no direct therapy for an FCE as we do not have a way to remove the fibrocartilage from the blood vessels in the spinal cord. We rely on time to allow the spinal cord to make new blood vessels or to open up the obstructed vessel. The immediate aftercare depends on how severely affected your pet is.
In dogs that cannot stand or move their limbs, keeping them rested on a soft, well-padded bed and rotating from left to right side every four to six hours is ideal to prevent bed sores. Owners may have to express their pet’s urinary bladder to prevent it from over filling and to reduce risk of developing a urinary tract infection. Some Veterinary Neurologists use an indwelling urinary catheter to help manage the bladder while patients are hospitalized.
To improve strength and coordination, physical therapy is key in the recovery phase. Examples of exercises used to help facilitate recovery include:
Walking in and out through weave poles and over cavaletti poles
Some alternative therapies that may help with improvement are hyperbaric oxygen therapy, laser therapy, and acupuncture.
The long term prognosis for recovering the ability to walk is good in most cases. Most dogs tend to show a slow but steady improvement in strength and mobility over 2-6 weeks. Not every dog will improve, in part due to the severity of the initial injury.
The chances of having a second FCE in the future are low.
Listen to an episode on Spinal cord disease in dogs and cats from Morris Animal Foundation's Fresh Scoop Podcast!