How To Tell If A Dog Has A Concussion: Emergency Veterinary Assessment Protocol

To accurately determine if a dog has a concussion, perform an immediate clinical assessment of their pupil symmetry, motor coordination, and level of consciousness. Watch for primary diagnostic indicators such as unequal pupil sizes, abnormal rapid eye movements, uncoordinated walking, or a dull, unresponsive mental state. Because secondary brain injury from swelling or internal bleeding can develop hours after an impact, identifying these signs early and seeking veterinary intervention is critical to preventing permanent neurological damage.

Immediate Safety and Pre-Assessment Protocol for Head Trauma

Evaluating a dog suspected of having a concussion—scientifically categorized as a traumatic brain injury (TBI)—requires immediate action but absolute physical caution. Pain, confusion, and fear alter a dog’s behavior. Even the most docile family pet may bite reflexively when experiencing cranial pain or neurological disorientation.

Before beginning your assessment, establish a safe, quiet, and well-lit environment to minimize external sensory stimuli, which can exacerbate intracranial pressure (ICP) and stress.

Emergency Preparation and Equipment Checklist

• Diagnostic Tools: A low-intensity LED penlight or a smartphone flashlight is essential for checking pupillary light reflexes.
• Physical Protection: A soft fabric muzzle or a roll of gauze to create a temporary muzzle. Do not use a muzzle if the dog is actively vomiting, exhibiting breathing difficulties, or bleeding from the mouth or nose.
• Transport Materials: A rigid board, plywood sheet, or a thick, flat blanket to serve as an emergency stretcher. This minimizes movement of the cervical spine during transport.
• Physical Environment: A quiet, darkened room for ocular testing, immediately adjacent to an easily accessible exit for swift vehicle loading.
• Prerequisite Baseline Knowledge: Familiarity with your dog's normal vital signs, including a healthy pink gum color, a heart rate ranging from 70 to 120 beats per minute (depending on breed size), and a respiration rate of 15 to 30 breaths per minute at rest.
• Estimated Assessment Window: 5 to 7 minutes. Do not delay emergency transport to complete a prolonged home evaluation if the dog is unconscious or actively seizing.

Clinical Step-by-Step Assessment for Canine Concussion

Follow these systematic neurological steps to evaluate the severity of a head injury. Keep the dog as calm and immobile as possible throughout this process.

Step 1: Perform the Ocular and Pupillary Assessment

The eyes are the direct window to your dog's brain health. Changes in pupil size, symmetry, and responsiveness are the most reliable indicators of localized brain swelling, cranial nerve compression, or brainstem damage.

1. Observe Pupil Symmetry (Anisocoria): In a moderately lit room, look directly at both of your dog's pupils. They should be identical in size. If one pupil is pinpoint (miotic) and the other is wide and dilated (mydriatic), your dog is exhibiting anisocoria. This indicates severe, localized pressure on one side of the brain.
2. Evaluate the Pupillary Light Reflex (PLR): Move your dog into a dimly lit space. Shine your penlight directly into one eye from a distance of about two to three inches. The pupil should quickly constrict (shrink). Remove the light, and it should dilate back to its original size. Repeat this test on the other eye. A slow, sluggish constriction or a complete lack of response (fixed pupil) indicates severe brainstem compromise.
3. Check for Involuntary Eye Movement (Nystagmus): Observe the eyes when the dog's head is stationary. If the eyeballs are constantly flickering horizontally, vertically, or in a circular motion, this indicates vestibular system disruption or brainstem trauma.

Warning: Do not touch or apply pressure to the eyeball itself, especially if there is visible swelling around the face or eye sockets. If the dog has sustained a facial fracture, manual pressure can cause permanent blindness or globe rupture.

Step 2: Evaluate Motor Function, Gait, and Posture

Brain trauma disrupts the pathways that coordinate movement, balance, and limb placement.

1. Observe the Gait (Ataxia): If the dog is conscious and able to stand, encourage them to walk a few steps on a non-slip surface. Watch for uncoordinated, wobbly, or "drunken" steps. Ataxia is a hallmark sign of cerebellar or vestibular dysfunction caused by trauma.
2. Check for Knuckling (Proprioceptive Deficits): While the dog is standing, lift one paw and place it so the top of the paw (the fur side) is touching the ground instead of the paw pads. A healthy dog will immediately correct their paw position. If the dog remains standing on the knuckles of their paw without correcting it, they are experiencing proprioceptive deficits, which point to spinal cord or brain pathway disruptions.
3. Identify Extensor Rigidity (Abnormal Posturing): If the dog is lying down and cannot stand, observe the posture of their limbs. If all four limbs are completely stiff and extended, or if the front limbs are rigidly straight while the back limbs are completely limp, this indicates severe decerebrate or decerebellate rigidity. This is a critical medical emergency.

Pro-Tip: If your dog cannot stand, do not force them upright. Forcing a neurologically compromised dog to stand can worsen spinal fractures or increase blood pressure to the brain, which accelerates cerebral edema.

Step 3: Determine the Level of Consciousness (LOC)

Neurological damage directly impacts a dog's awareness and interaction with their environment. Classifying their mental status helps veterinarians understand the depth of the brain injury.

1. Assess Environmental Awareness: Call your dog's name in a normal tone. A normal, uninjured dog will look toward you immediately. A dog with a concussion may be obtunded—meaning they are dull, slow to respond, and require louder or repeated prompts to acknowledge your presence.
2. Evaluate Pain Response (Stupor): If the dog does not respond to verbal commands or clapping, check their response to physical stimulation. Gently pinch the skin between their toes. A stuporous dog will pull their leg away or whine only in response to this painful stimulus, remaining otherwise unresponsive.
3. Recognize Comatose States: If the dog does not react to vocalizations, movement, or a firm toe pinch, they are in a coma. Keep their airway clear, position their head flat or slightly elevated, and transport them to an emergency facility immediately.

Step 4: Inspect Systemic Vitals and Perfusion Indicators

A head injury often triggers systemic shock or blood pressure anomalies as the body struggles to maintain oxygen delivery to the damaged brain tissue.

1. Examine Mucous Membrane Color: Gently lift your dog's upper lip to view the gums. Healthy gums are a bright, bubblegum pink. Gums that appear pale, white, blue (cyanotic), or muddy gray indicate a lack of oxygen or severe shock.
2. Measure Capillary Refill Time (CRT): Press your thumb firmly against the pink gum tissue above the canine tooth for two seconds, then release. The tissue will turn white. Count how many seconds it takes for the pink color to return. A healthy return time is under two seconds. If it takes longer than two seconds, circulation is compromised.
3. Monitor Breathing Patterns: Count the respirations. Extremely slow, shallow breathing, or rapid, erratic panting when the dog is not hot or stressed, indicates damage to the respiratory center located in the brainstem.

Canine Triage Criteria: Modified Glasgow Coma Scale (MGCS)

Veterinary emergency clinicians use the Modified Glasgow Coma Scale to objectively assess the neurological status of dogs with craniocerebral trauma. This scale scores three clinical categories from 1 to 6, with a total score ranging from 3 (worst prognosis) to 18 (best prognosis).

Post-Traumatic Complications and Secondary Brain Injury Risks

Primary brain injury occurs at the exact moment of physical impact. Secondary brain injury, however, develops minutes to hours later due to biochemical cascades, swelling, and bleeding within the skull. Managing these complications at home while preparing for transport can save your dog's life.

Scenario 1: Delayed Onset of Lethargy and Neurological Decline

• Root Cause: Cerebral edema (progressive swelling of the brain tissue) or intracranial hemorrhage (bleeding inside the skull). Because the skull is a rigid bone structure, swelling tissue and accumulating blood have nowhere to expand, causing a massive increase in intracranial pressure.
• Actionable Fix: Immediately elevate your dog's head and neck at a 30-degree angle relative to their body during transport. Use a rolled-up towel or small blanket under their head. Ensure their neck remains completely straight to prevent compression of the jugular veins, which would block blood leaving the brain and further increase pressure. Do not administer human pain relievers like ibuprofen or aspirin, as these thin the blood and can cause fatal brain hemorrhages.

Scenario 2: Post-Traumatic Seizures

• Root Cause: Severe cortical irritation, hypoxia, or localized structural damage in the cerebral hemispheres. This causes sudden, uncontrolled electrical discharges in the brain.
• Actionable Fix: Do not attempt to restrain your dog or put your hands near their mouth, as they may bite uncontrollably. Clear the immediate area of sharp objects, hard furniture, or stairs. Note the exact start and end time of the seizure. If the seizure lasts longer than two minutes, wrap the dog’s torso in a cool, damp towel to prevent heatstroke (hyperthermia) brought on by intense muscle contractions, and transport them immediately to an emergency clinic.

Scenario 3: Sudden Vomiting and Aspiration Risk

• Root Cause: Stimulation of the vestibular centers or direct pressure on the emetic center located within the brainstem.
• Actionable Fix: If the dog is lying down and starts to vomit, quickly position their head lower than their stomach to allow gravity to pull the vomit out of their mouth. This prevents them from inhaling the vomit into their lungs, which causes aspiration pneumonia. Gently wipe their mouth clear of debris with a clean cloth. Keep them fasted—do not offer any food or water, as their swallowing reflexes may be temporarily paralyzed.

Frequently Asked Questions

Can a dog sleep after a concussion?

Yes, rest is a crucial component of brain healing, but you must monitor them closely. During the first 24 hours following a head injury, do not allow your dog to sleep uninterrupted for more than two to three hours at a time. Wake them gently to verify they can recognize you, stand, walk normally, and that their pupils remain equal in size and responsive to light.

How long does it take for a dog to recover from a concussion?

Recovery time is highly variable and depends on the severity of the primary impact and how quickly veterinary treatment was initiated. Mild concussions often resolve within three to seven days of strict crate rest and supportive therapy. Severe head injuries involving brain swelling, skull fractures, or internal bleeding can take several weeks to months, and some dogs may have permanent neurological deficits.

Can I give my dog over-the-counter pain medication for a head injury?

No, never administer any over-the-counter human pain medications like ibuprofen, acetaminophen, or aspirin to a dog with a suspected concussion. These medications can cause acute kidney failure, induce gastrointestinal bleeding, thin the blood (which worsens intracranial hemorrhages), and interfere with critical emergency drugs that the veterinarian may need to administer immediately upon arrival.

What are the long-term effects of a canine concussion?

While many dogs recover completely, severe or repeated head trauma can lead to chronic neurological complications. These long-term effects include post-traumatic epilepsy (chronic seizures), permanent behavioral changes such as increased anxiety or aggression, diminished cognitive function, loss of vision, or a permanent head tilt due to vestibular damage.

How do veterinarians diagnose and treat a concussion?

Veterinarians diagnose concussions through thorough neurological exams, blood work, and advanced imaging like CT scans or MRIs to look for skull fractures and internal bleeding. Treatment focuses on reducing brain swelling using specialized intravenous fluids like mannitol, providing supplemental oxygen therapy, administering anti-seizure medications, and providing intensive monitoring in a controlled hospital environment.

Secure Emergency Neurological Care for Your Companion

If your dog has sustained an impact to the head and is showing any signs of neurological dysfunction, immediate veterinary intervention is required to manage intracranial pressure. Contact your nearest emergency veterinary hospital or a board-certified veterinary neurologist immediately to guarantee your pet receives life-saving diagnostics and treatment.