What is Brachial Plexus Avulsion?
You may notice that your canine begins to limp or have a limb that drops. This may follow an injury and may impact any of his limbs. The drop may be a noticeable inability in flexing and controlling the limb and therefore it just hangs there.
This injury can look similar to a less severe injury, or your canine may not want to put pressure on a broken bone or cut. Your canine may not appear to be in any pain making it difficult to identify what is going on.
The brachial plexus are the last 3 cervical and first 2 thoracic nerves in your canine’s spine which impacts his shoulders. When these nerves are torn, ripped or injured it is referred to as an avulsion. This tends to happen if your canine is hit by a car, or if he falls and there is displacement of the thoracic (backbone) limbs.
Symptoms of Brachial Plexus Avulsion in Dogs
Symptoms will include the loss of use of your canine’s limbs, changes in his behavior, and other possible medical symptoms.
- Horner’s Syndrome (drooping eye, small pupil, sunken in eye, prominent third eyelid)
- Paralysis of a limb
- Difficulty controlling a limb
- Limbs dragging
- Not putting weight on a limb
- Lack of pain or significant pain when examined
There are three types of brachial plexus avulsion and they are dependent on what part of the spine is impacted.
Cranial avulsions (C6-C7)
- Few clinical signs and symptoms
- Your canine will most likely be able to bear weight on the limb
- Loss of shoulder movement
Caudal avulsions (C8-T2)
- More common
- Cause severe clinical signs
- Your canine may not be able to extend his elbow or bear weight
- Dragging of the limb
- May carry the limb flexed off the ground
Complete avulsions (C6-T2)
- Sensory signs are common
- Partial Horner’s Syndrome
Causes of Brachial Plexus Avulsion in Dogs
The cause of brachial plexus avulsion is typically an injury, however there are other causes of the condition as well:
- If your canine was hit by a car
- If your canine fell from a significant height
- If your canine was grabbed incorrectly or roughly
- Neuromuscular disease
- Endocrine system disorders
- Immunization side effect
Diagnosis of Brachial Plexus Avulsion in Dogs
If you begin to notice that your canine is not putting weight on a limb, dragging a limb, or if there was recent injury, you will want to contact your veterinarian. It will be important to go to your veterinarian or emergency veterinarian prepared to share any recent injuries, falls or events such as if your canine was hit by a car.
Your veterinarian will want to perform a full body exam to determine any obvious injuries or signs of brachial plexus avulsion. Your veterinarian will want to test your canine’s nerve reactions and see if there is any damage. This may include testing if your canine feels pain when pinched or poked.
Your veterinarian may want to perform an MRI as it is the imaging tool of choice to determine a brachial plexus injury. Electrodiagnosis testing can also be performed, this test will involve inserting a needle into your canine’s muscle to see how it responds to stimuli. This will help your veterinarian to determine the cause of your canine’s limb concerns 7 to 10 days’ post injury.
Treatment of Brachial Plexus Avulsion in Dogs
Treatment options are unfortunately limited and long term prognosis is not promising. Your veterinarian may suggest surgery to try and correct some of the damage done to your canine’s nerve endings. It should be noted that if it is a full avulsion (full tearing of your canine’s nerve endings from the spinal cord) the prognosis is poor.
Surgery can be done to repair some of the damage done to your canine’s nerve endings. Some of the surgery options are: coaptation splintage, tendon transposition, nerve transposition, ankyloses and amputation. The splintage is done to prevent your canine from harming his limb and is done along with physical therapy and anti-inflammatory medications.
Tendon transposition is done by cutting the tendons and either reconnecting them or loosening them to provide your canine with more use of the limb. Nerve transposition is done by reattaching the nerves to other places to try and provide your canine with some of use of his limbs. Amputation may be suggested if your canine will be dragging the limb causing it ongoing injury or if he is self-mutilating the limb. Long term prognosis is poor for full avulsion, however for partial there is a possibility for recovery with treatment.
Recovery of Brachial Plexus Avulsion in Dogs
Your canine will most likely need ongoing care depending on the severity of his brachial plexus injury. These appointments will be done to determine his condition is getting any worse or if there is any improvement.
Should he have surgery there will be follow up need per the direction of your veterinarian. A full recovery can be expected within 2 months of surgery. Your veterinarian may also suggest physical therapy once surgery is done and also to try and recover some function.