Traumatic Brain Injury in Horses

What Is Traumatic Brain Injury in Horses?

Traumatic brain injury (TBI) occurs when there is trauma to a horse’s head that results in damage to any part of the brain, including the blood vessels and nerves within the brain. TBI is considered a medical emergency. If you suspect your horse may have suffered a traumatic brain injury, call your veterinarian immediately. If it can be done safely, move your horse to a cool, clean, and padded area. Be sure to exercise caution around your horse as they may be unstable and unpredictable at this time.

Symptoms of a traumatic brain injury may appear similar to symptoms of other neurological diseases. The difference with TBI is that it’s caused by a sudden trauma event, whereas other neurologic problems may be caused by infections, toxins, or congenital diseases. Trauma is always linked with TBI in a horse.

Symptoms of Traumatic Brain Injury in Horses

• Fainting episode

• Seizures

• Sudden blindness

• Bleeding from nose or ears

• Difficulty breathing

• Unresponsiveness

• Lying down and not wanting to get up (down horse)

• Lack of balance

• Abnormal eye movement

• Unequal sized eye pupils

If you see your horse experience a traumatic event and are unsure if it caused TBI, call your veterinarian immediately.

Causes of Traumatic Brain Injury in Horses

• Flipping over backwards

• Kicked in the head

• Running into fixed object (e.g. fencepost)

• Getting hit by moving object (e.g. vehicle)

• Fighting

• Trailer accidents

How Veterinarians Diagnose Traumatic Brain Injury in Horses

As with all equine medical conditions, your veterinarian will take a history and perform a full physical exam. They may suspect a traumatic brain injury if they see any of the clinical signs listed above and it fits with the history.

In order to make a definitive diagnosis of traumatic brain injury, your horse needs to have a computed tomography (CT), and possibly a magnetic resonance imaging (MRI) performed.

• A CT scan performed within the first 24 hours from injury will identify damage to the brain tissue by looking for bruises on the brain. It will also look at the bones in the head and neck to identify fractures.

• An MRI performed 24 to 72 hours after a traumatic brain injury will look for secondary swelling and inflammation in and around the brain. It is also the best tool to look at damage done to the nerves and blood vessels within the brain.

These tests must be performed in an equine hospital. Though these tests are ideally taken in the event of a TBI, it is not always possible to do so. Your veterinarian will determine if the horse is safe enough to travel in a trailer to an equine hospital. Second, consideration for these tests must be taken into account since both require either general anesthesia or sedation. A horse that is already having neurological problems from a traumatic brain injury may have increased difficulty recovering from general anesthesia or sedation. Your veterinarian can help you make the best decision based on your horse’s health.

If the horse cannot be transported, tests that may help diagnose a traumatic brain injury that can be done in the field setting include radiographs and upper airway endoscopy.

• Radiographs of the skull are used to identify fractures, abnormal pockets of air surrounding the skull, or blood in the sinus cavities.

• An endoscopy will look in the guttural pouches for bleeding.  

Treatment of Traumatic Brain Injury in Horses

A traumatic brain injury needs to be treated quickly and aggressively. The first thing your veterinarian will do is make sure your horse is in a safe location and stop any active bleeding or seizures. After that, they will place an intravenous catheter (IV) and administer anti-inflammatory and pain medications like flunixin meglumine (Banamine) and butorphanol.

Additionally, they will administer either hypertonic saline or mannitol through the IV catheter to decrease brain swelling; this will be followed with IV fluids to keep the horse hydrated. If the horse has an elevated temperature, try to cool them with fans or hose them down with cold water. 

If the horse can be transported to an equine hospital, additional monitoring and treatments can be pursued. This will include bloodwork to monitor levels of blood sugar, hydration, and inflammation. Hospitalization will also allow for monitoring and treatment of blood pressure and blood oxygen levels. After the horse has been stabilized, surgery to fix any fractures may be pursued, if necessary.

The use of steroids as treatment for traumatic brain injuries in horses has become controversial, due to the fact these medications have been associated with poor outcomes in human patients. With the potential for adverse effects and no proven positive effects, their use is no longer recommended in horses.

The use of other anti-inflammatories and antioxidants, like vitamins B, C, and E and dimethyl sulfoxide (DMSO) are routinely used to treat TBI in horses. These medications are often prescribed despite no research-based proven benefits. Rather, these medications have been proven successful in the veterinarian community when it comes to treating TBI in horses.

Recovery and Management of Traumatic Brain Injury in Horses

Recovery from traumatic brain injury is dependent on the location and severity of the injury. Some horses with minimal damage may return to normal function, however other horses may have permanent, life-altering damage. Overall survival rate is approximately 62%. Horses that remained lying down for 4 or more hours after injury are less likely to recover. A more favorable prognosis is seen in horses that maintain a normal mental awareness, blood cell levels in the normal range, and no fractures to the underside of the skull. Additionally, horses that can be stabilized and treated promptly are expected to have a better recovery.

It is advised not to return a horse with a traumatic brain injury to work for at least a month after injury, and when doing so, increase the work gradually. This will give the horse time to acclimate and the handler the opportunity to notice any delayed injuries.

During this recovery time, the horse should remain in a safe environment. This should include a stall with extra bedding, and they should never be left out in pasture alone. Anything that causes loud noises or a trigger that would scare your horse should be avoided. If your horse has permanent effects to their balance, coordination, or eyesight, they may need to be retired. All horses with a history of a traumatic brain injury should be cleared by your veterinarian before returning to work.

In order to prevent a traumatic brain injury, a padded helmet may be useful. This would be ideal for a situation such as when horse owners halter break a horse. Always ensure your horse is tied well during trailering or washing to prevent accidents or falls that may result in a head injury.