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VetVine Client Care

Posted On Jun 23, 2025

Updated On Jul 07, 2025

Head Trauma

Emergency & Critical Care

Head trauma can be caused by a variety of different injuries. The most common categories are blunt trauma and penetrating trauma. The most common type of blunt trauma that we see in veterinary medicine is the "hit by car" patient. These patients account for 52% to 66% of all head trauma cases. Forms of penetrating trauma include gunshot wounds, bite wounds, and stab wounds. Bite and stab wounds account for 6% to 29% of head trauma cases in veterinary medicine.

Traumatic brain injury (TBI) can develop in association with head trauma; however, it's important to remember that not all patients presenting with head trauma will develop TBI. TBI results in neurologic impairment with an abnormal modified Glasgow Coma Score, and mortality rates range from 18% to 24% in veterinary patients. While prognostic indicators and efficacy of various therapies have been well studied in people, they had not been widely evaluated in veterinary medicine until several years ago.

A variety of scoring systems are available and utilized to assess veterinary patients in the clinical setting (e.g. pain, quality of life, etc.) In particular, for patients presenting with trauma, the Animal Trauma Triage Score (ATT score) can be used to predict outcomes. The ATT score consists of six different categories and four different grading systems. It’s important to point out that a lower score (closer to 0) indicates a better prognosis, whereas a higher score (up to 18) suggests a more guarded prognosis or severe condition. In addition to the ATT score, the Modified Glasgow Coma Score (MGCS) has been used to predict prognosis in dogs with head trauma and TBI. It provides an objective measurement of neurologic status and can help gauge patient response to therapy. This system has shown good association with outcome parameters.

A study published in 2015 reported on the prognostic value of clinical exam findings, clinical pathology, and various scoring systems in dogs presenting with head trauma. The study was retrospective and conducted at a veterinary teaching hospital over a three month period back in 2011. It included 72 dogs with confirmed head trauma, which had occurred within five days of admission. Patients with a prior history of neurologic disease were excluded.

The study examined several variables: patient signalment, cause of trauma, physical exam findings, vital signs, blood pressure, pulse oximetry, and laboratory data (blood gas indices, blood glucose, electrolytes, lactate, CBC, and serum biochemistry profiles). Severity scores evaluated included the MGCS, a mentation score, and the ATT score. Therapies that were analyzed included mannitol, hypertonic saline, oxygen support, and various other drugs (benzodiazepines, phenobarbital, and corticosteroids). Outcomes were defined as survival to discharge or nonsurvival (either euthanized or deceased naturally).

The median age of dogs in the study was 2.2 years, which is not surprising since younger patients more often sustain trauma. 89% of these patients had blunt trauma—55% of which were motor vehicle accidents. The remaining 11% experienced penetrating trauma. Neurologic deficits were seen in over 89% of the study population, meaning nearly all had an abnormal MGCS of less than 18. Overall mortality was 15.3%, lower than previously reported. Of those that did not survive, 90.9% were euthanized and 9.1% died naturally.

The main predictors of nonsurvival were variables indicating decreased oxygenation and perfusion: low pulse oximetry, metabolic acidosis (defined as low pH, bicarbonate, and base excess), elevated lactate, potassium, or BUN, and low total protein or albumin. Additional predictors of nonsurvival included treatment with hypertonic saline and the need for endotracheal intubation. Patients with more severe TBI - as evidence by increased intracranial pressure, hypotension, and respiratory compromise - required aggressive interventions such as mannitol, oxygen, and intubation.

All three scoring systems showed prognostic utility. This is clinically helpful because they are readily available and useful for serial monitoring. Specifically, the MGCS score (range from 3 to 18) demonstrated that dogs with higher scores had a better prognosis. Dogs with a score of 15 had a 100% probability of survival, while those with a score of 8 had only a 57% chance of survival. For the ATT score (range from 0 to 18), a lower score (<7) is better. Dogs with a score of 9 only had a 50% survival probability. The mentation score ranged from 0 to 4, and those with scores ≤2 had 100% survival—again reinforcing that lower scores are better.

Blood glucose was another variable worth noting. Hyperglycemia has been associated with more severe TBI in dogs and cats, but not with outcome. Blood pressure, a key variable in human studies, was not adequately evaluated in this study due to small numbers. In people, hypotension is predictive of nonsurvival.

The Cushing’s reflex can also be seen in patients with traumatic brain injury and increased intracranial pressure. This presents as a clinical syndrome of elevated blood pressure (often >160 mmHg with Doppler) and bradycardia (heart rate typically <100 bpm). This paradoxical response stems from decreased cerebral perfusion that then triggers sympathetic vasoconstriction and a baroreceptor-mediated reflex bradycardia.

In conclusion, preventing and treating cerebral hypoxemia and hypotension is critical to avoid secondary brain injury and patient mortality. While we cannot change the primary trauma, we can minimize secondary injury by maintaining normal physiologic parameters and ensuring oxygenation within the first 24 hours post-trauma. The scoring systems validated in this study—the ATT score and MGCS—are useful for assessing prognosis and guiding treatment but should not be used as the sole tool in prognostication. These systems are valuable for serial monitoring, especially when multiple doctors are involved in care or when patients are transferred between facilities. Establishing a baseline score aids in determining patient improvement or deterioration.

Use scoring systems on admission to assess severity and guide supportive care decisions. In addition to these scores, it’s essential to always document patient condition thoroughly at presentation, describe injuries clearly, and to always record reasons for euthanasia (if euthanasia is elected). This helps reduce subjectivity between clinicians and supports better interpretation of examination findings.

Treating Head Trauma

Treatment of head and/or spinal trauma can be challenging because, in addition to the initial or primary injury, these patients often experience perpetuation and propagation (secondary injury) due to a cascade of events including progressive hemorrhage or edema and production of oxygen derived free radicals.

Furthermore, patients with severe head trauma often have injury to other organs including the lungs, liver or spleen - particularly those that have been struck by a motor vehicle (hit by car). These patients often develop hypotension associated with shock and/or intracavitary hemorrhage. Vasodilation then occurs in vital organs (brain, heart, kidneys) in an effort to maintain perfusion to those organs. In the brain, vasodilation occurs in an effort to maintain cerebral perfusion pressure (CPP). In patients with head trauma, if there is concurrent edema or hemorrhage in the cranial vault - the increase in intracranial pressure (ICP) can worsen the CPP. Therefore, to preserve CCP, we must normalize the mean arterial pressure (MAP) of the patient. As such, it is critical to provide intravenous fluids in an effort to normalize the patient's mean arterial blood pressure.

CPP = MAP - ICP

Treatment

Treating patients with head trauma can be challenging. In a past VetVine webinar, Elisa Mazzaferro, MS, DVM, PhD, DACVECC shared these reminders:

1) Elevate the head - the head and neck should be elevated 15-30 degrees

2) Avoid compression or occlusion of the jugular vein and jugular venipuncture until intracranial pressure and cerebral perfusion is stabilized

2) Treat seizures with anticonvulsants if they occur

3) Provide analgesia and sedate patients if they are vocalizing, trembling, thrashing or showing signs of pain in an effort to avoid increases in cerebral metabolism and oxygen consumption (avoid ketamine and alpha-2 agonists)

Despite how dire patients may appear at presentation, many—particularly young ones—can make miraculous recoveries. So, give them a chance!

Reference: Retrospective evaluation of prognostic indicators in dogs with head trauma: 72 cases (January-March 2011). J Vet Emerg and Crit Care, 2015; 00:1-9. doi 10.1111/vec.12328