What is fibrocartilaginous embolism (FCE)?
Fibrocartilaginous embolism is a syndrome where fibrocartilaginous material dislodges and becomes lodged in a spinal or vertebral blood vessel, leading to spinal cord injury due to lack of bloody supply and oxygen.
Fibrocartilaginous emboli are associated with the intervertebral discs. Intervertebral discs are located between vertebrae and act to stabilise and support the spinal column. The exact mechanism by which fibrocartilage emboli enter the vasculature is not known but there are a few proposed mechanisms. The resulting infarction (damage due to lack of blood supply) causes secondary metabolic and biochemical events leading to spinal cord injury and cell death. Often other blood vessels open to facilitate collateral circulation to the spinal cord and the oedema surrounding the infarcted area resolves, explaining how most dogs can recover relatively soon after the accident.
What breeds are at increased risk of FCE?
FCE most commonly affects medium to large breed dogs, including Labrador Retrievers, German Shepherds, Boxers and Staffordshire Bull Terriers, however it may also occur in small breed dogs, most commonly miniature Schnauzer. Young adult dogs are most commonly affected.
How can I tell if my dog has a fibrocartilaginous embolism?
A history of mild trauma or vigorous exercise is common in dogs presenting with FCE.
The clinical signs will vary for each patient, and are often rapid in onset with no progression, or they may progress (worsen) over the first 24 hours. Often the first sign of a problem is a pain response – normally a yelp or vocalization, when the embolism first happens. Following this, pain is not a feature of this condition.
Neurological signs depend on the segment of spinal cord damaged and are typically asymmetrical. Neurological signs may vary from weakness (-paresis) to complete paralysis (-plegia) and may affect one limb, one side of the body or the hind limbs only. Your pet may also lose its ability to urinate or defecate.
How is fibrocartilaginous embolism diagnosed?
Fibrocartilaginous emboli may be strongly suspected on the basis of the acute onset, non-progressive clinical signs; however diagnostic imaging is required to confirm the diagnosis.
MRI is the most accurate advanced imaging technique for the evaluation of FCE. However, dogs must lie completely still for their MRI scan, and this is only possible with general anaesthesia. Your pet will have dedicated care during their MRI or CT scan by one of our nurses from our nursing team who are all trained and experienced in anaesthesia and sedation. We do have an in-house CT machine however it is only possible to see an FCE on an MRI scan, this has to be done off-site but still under our care.
How is fibrocartilaginous emboli treated?
Fibrocartilaginous embolism is a non-surgical spinal condition unlike intervertebral disc disease which is often managed surgically, but both conditions have similar clinical signs as a result of spinal cord injury. This is why MRI is essential in order to achieve the correct diagnosis.
Once a diagnosis of fibrocartilaginous embolic myelopathy is obtained, strict cage rest, physiotherapy and supportive therapy become the most important considerations in rehabilitation. Your dog will be assessed by our in-house physiotherapist who will design a physiotherapy and rehabilitation program specifically for your dog. Physiotherapy plays a vital part in the treatment of animals with fibrocartilaginous embolic myelopathy, inactivity and recumbency results in decreased joint movement, stiffness and muscle weakness and contracture which all hinder a smooth road to recovery.
Supportive nursing care will also be provided by our patient care team during their stay in hospital, which includes regular turning of your pet to prevent pressure sores, urinary care and faecal management. Intravenous fluids may be required to ensure adequate hydration and perfusion to the affected area of the spinal cord.
Your pet will be hospitalised following fibrocartilaginous embolism until they show signs of improvement as well as a return to voluntarily urination function, if urinary incontinence is present in the first instance.
What is the prognosis of fibrocartilaginous embolism?
The prognosis for recovery from a fibrocartilaginous embolism is based on the severity of the spinal cord injury. Ultimately, the rate and extent of recovery is variable and difficult to predict but can take days, to weeks or months. The majority of dogs may show signs of improvement within the first 1-2 weeks, whereas full recovery may take much longer. Patients that do not demonstrate improvement within 2 weeks of onset of clinical signs are considered to have a poorer prognosis compared to patients that demonstrate rapid improvement.
At North Coast Veterinary Specialists and Referral Centre we will provide you with a support team to include mobility slings and devices as well as physiotherapy and hydrotherapy, all of which can be provided on an out-patient basis through our rehabilitation service once your dog has been discharged from hospital. During your initial appointment one of our physiotherapists will assess your dog and design a program specific for rehabilitation and will also advise you of how often appointments are required.
Although the pathophysiology of the fibrocartilaginous embolic myelopathy is not fully understood, once an animal recovers there is very little chance of recurrence.