Fibrocartilaginous Embolus (FCE) in Cats

By Tammy Hunter, DVM; Krista Williams, BSc, DVM, CCRP; Robin Downing, DVM, DAAPM, DACVSMR, CVPP, CRPP

What is fibrocartilaginous embolus (FCE)?

FCE is an abbreviation for “fibrocartilaginous embolus/emboli” (“emboli” is the plural of embolus). Fibrocartilage is connective tissue found primarily in the joints. An embolus is material that travels through the circulation and blocks a blood vessel.

"An FCE is the acute death of part of the spinal cord caused by the embolus of fibrocartilaginous material."

Another term for FCE is “fibrocartilaginous embolic myelopathy”, with the word “myelopathy” describing a problem with the spinal cord. An FCE is the acute death of part of the spinal cord caused by the embolus of fibrocartilaginous material.

The material is believed to come from a damaged intervertebral disk, then travels in the circulation where it blocks a blood vessel that supplies the spinal cord with oxygen and nutrients. The precise way the material gets into the blood vessels is unknown.

Is this condition more common in some breeds than others? Does age have anything to do with FCE?

FCE is a rare condition in cats. Most patients are middle-aged or older.

What causes FCE?

In dogs, it is most common for an FCE to occur following a mild trauma or during vigorous exercise. This condition is so rare in cats that it has not been reported consistently. FCE occurs suddenly, and affected cats typically cry out in pain. Most often, the pain subsides within a few minutes, and signs of weakness and/or paralysis develop quickly. These cats are generally stable within 12 to 24 hours.

My cat’s pain seems to be gone, but her right rear leg is useless. Is it common for only one leg to be affected? What other symptoms do these cats exhibit?

It is common for the cat with FCE to be relatively comfortable within a short time. In general, nervous system deficits are localized to one side of the body, and the other side of the body is either mildly affected or completely normal.

Occasionally, the embolic lesion is positioned such that both sides of the cat’s body are affected. The level of the cat’s dysfunction depends on what level of the spinal cord is damaged, and the signs may be as simple as incoordination or as serious as paralysis.

How is FCE diagnosed?

Cats with FCE are typically diagnosed by findings on a physical exam. Spinal X-rays in affected cats are usually normal. The most common and best diagnostic test for FCE is magnetic resonance imaging (MRI).

How is FCE treated?

Most cats who experience FCE are hospitalized in the acute phase so that diagnostic tests can be performed to rule out other causes of acute-onset weakness or paralysis. If the cat cannot walk, then intensive nursing care is needed, including keeping the cat on a padded surface and turning them frequently to prevent pressure sores. It is important to encourage these cats to move and walk as soon as possible.

"Using assistive devices, like a lightweight fabric harness, can facilitate both healing and early restoration of mobility."

There is no specific medical treatment for FCE. Instead, the emphasis is on supportive care and physical assistance. Using assistive devices, like a lightweight fabric harness, can facilitate both healing and early restoration of mobility. Physical rehabilitation, including assisted exercises, muscle stimulation, and hydrotherapy in an underwater treadmill or land treadmill, can also help these cats regain strength. Yes, cats can learn to walk on an underwater treadmill!

Once other causes of weakness or paralysis are ruled out, activity should be encouraged to prevent, or at least minimize, muscle atrophy. Most improvement for these cats occurs in a few days to weeks, but every cat is different.

Do I need to worry about this happening again? Are there any other potential complications?

Depending on the lesion, a cat may have difficulty emptying their bladder, requiring assistance and vigilance to prevent urinary tract infection. Also, depending on the lesion, the cat may have stool incontinence.

If the clinical signs of FCE progress during the initial phases of the disease, it indicates progressive destruction of the spinal cord that is not reversible and, unfortunately, euthanasia may be indicated.

Recovery from the weakness or paralysis caused by FCE is slow and gradual and often reaches a plateau. Some cats appear to make a complete recovery. Your veterinary health care team can assist with guidance and support following FCE. Recurrence is unlikely.

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