Skull fracture in horses a relatively common injury

Te Papa Conservator Robert Clendon removes Phar Lap’s skull from the rest of the skeleton, before extracting one of the incisor teeth.
The skeleton of legendary racehorse Phar Lap, at New Zealand’s national museum, Te Papa. © Jean-Claude Stahl/Te Papa

Accidental injuries can happen to any horse at any time, and a fairly common and usually catastrophic injury is trauma to the head resulting in fracture of the skull, writes veterinarian Dr Neil Williams.

Horses often are victims of accidental injury. Their gregarious nature, social hierarchy, heightened flight response, and handling and confinement by humans puts them at increased risk of trauma.

The head of a typical adult horse weighs more than 40 pounds (18kg). This, coupled with the long neck placing the head well outside the center of mass, causes the head to strike the ground with tremendous force during a fall. Also, the speed and strength of a horse can result in severe impact of the head against an object when rearing or running.

Over a five-year period, the University of Kentucky Livestock Disease Diagnostic Center has diagnosed 34 cases of skull fracture, with a yearly average of 6.8 cases. These were diagnosed in several breeds, with Thoroughbreds predominating. The affected horses ranged in age from 2 days to 23 years. Most cases were adult horses, but yearling and younger horses were affected as well.

Horses suffering a skull fracture often had a history of being handled with the horse rearing and flipping over, striking the head on the ground, or hitting its head on an overhead structure such as a trailer or stall ceiling. In other instances the history indicated the horse running directly into an object, such as a tree, fence, or barn. Occasionally, the horse was simply found dead with the causative event not being observed. The clinical signs in horses suffering a skull fracture included ataxia, recumbancy, paralysis, blindness, nystagmus, seizures, coma, and death. Hemorrhage from the nose or an ear was sometimes observed. Medical treatment was usually attempted; however, the horses often died or the severity of the injury necessitated euthanasia.

Cutting-edge imaging is improving equine head and spine diagnoses.
Cutting-edge imaging is improving equine head and spine diagnoses. Left, the horse’s head positioned within a CT gantry. The cradle and sand bag provide extra stability during CT scanning.

The diagnosis was made or confirmed at necropsy. The pathological findings among cases were similar. These sometimes included scrapes or excoriation of the skin on the head, and bruising and hemorrhage of the subcutaneous tissue at the point of impact. Hemorrhage in an ear canal, nasal passages, or a gutteral pouch was not unusual.

Commonly, there was epidural hemorrhage and tearing of the meninges, with hemorrhage into the brain and around the anterior cervical spinal cord. Fractures involved many of the different bones comprising the skull. The structure of the skull makes the occurrence of one fracture unlikely. The force resulting in a fracture and displacement in one area is transferred across the skull, fracturing another area. The occipital bone was most commonly fractured with a concurrent fracture of the basisphenoid bone. These fractures sometimes involved the acoustic meatus, with bleeding into the ear.

Fractures of this type are typical in a horse that flips over backward, striking its head. In contrast, running into an object or being kicked was associated with fracture of the frontal bone. Other bones fractured in this type of injury included the parietal, temporal, and zygomatic bones. Fractures of the frontal bone were often associated with hemorrhage into the frontal sinus and nosebleed.

It is important to recognize that horses are susceptible to this type of injury and how serious head injury can be. Special care is warranted when handling extremely nervous or “flighty” horses so that they are not put in situations or an environment where injury is more likely to occur if the horse becomes unruly or panics.

3 thoughts on “Skull fracture in horses a relatively common injury

  • January 16, 2017 at 2:05 pm

    I have had two horses with skull fractures.
    One is a Dutch warmblood throughbred cross who ran into a guy wire for a telephone pole. She showed an abrasion on her forehead. The vet nonchalantly assumed it was just a scrape until she palpated the area and felt the fracture. The power company provided a protective cover for the wire that is more visible.
    The other was a TB mare who came in from the pasture with a depressed place in her forehead (that is still there) and a severe tongue injury. The cause of the injury is not known but we infer that it was either a kick or a collision with a tree branch.
    Both lived.

  • January 17, 2017 at 11:35 am

    Wheres mention of abuse and violent training tactics? Its a seriously diminished issue and fractures can be and have been caused by people punching, hitting, or striking with objects a horses head. People asume horses are not breakable and we should investigate skull fracture in accusations of abuse scenarios as well. Maybe the next serious abuse case you can get your hands on those horses and substantiate this as well as show the severity of the abuse for court use and new legislation.

  • May 1, 2020 at 5:06 pm

    My almost 3yr old Appalossa mare just ran headlong at full speed into a 6″ wooden fence posts 2 nights ago and killed herself. From the evidence presented to us, she hit her face slightly to the right but the length of her skull, followed closely by her chest/right shoulder, resulting in her immediate collapse, she rolled away from the fence and there was no evidence of any attempts to struggle or stand. She simply died. She would have been 3 on June 20th. Goodbye Reisen ❤


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