Can Dogs Get Concussions? A Veterinary Science Guide to
Can dogs get concussions? Yes. Learn the veterinary science behind canine traumatic brain injury, symptoms to watch for, and when to rush to the ER.
The Neuroscience of Canine Concussions: What Happens Inside the Brain
When a dog's head sustains a significant impact — from being hit by a car, colliding with another dog during play, falling from a height, or striking a solid object — the brain undergoes a cascade of neurochemical events that mirrors what researchers observe in human concussion patients.
The Neurometabolic Cascade
According to research published in the Journal of Neurotrauma and summarized in the Merck Veterinary Manual, the following sequence occurs within minutes of a concussive impact:
- Immediate ionic flux (0-5 minutes): Mechanical stretching of neuronal membranes causes a massive, indiscriminate release of excitatory neurotransmitters — primarily glutamate — into the extracellular space. Potassium ions flood out of cells while calcium ions rush in.
- Energy crisis (minutes to hours): The sodium-potassium pumps work overtime to restore ionic balance, consuming enormous amounts of ATP (cellular energy). Cerebral glucose metabolism spikes by up to 80% while cerebral blood flow paradoxically decreases, creating an energy supply-demand mismatch.
- Mitochondrial dysfunction (hours to days): Excess intracellular calcium accumulates in mitochondria, impairing oxidative phosphorylation and triggering the production of reactive oxygen species (free radicals) that damage cellular structures.
- Axonal injury (days to weeks): The mechanical shearing forces and chemical damage compromise the structural integrity of axons — the long projections neurons use to communicate. In severe cases, this leads to diffuse axonal injury (DAI), which is associated with prolonged neurological deficits.
- Neuroinflammation (days to months): Microglial activation and inflammatory cytokine release create secondary damage that can persist long after the initial impact.
The key distinction between canine and human concussions lies in detection. Human athletes can report subjective symptoms — "my head hurts," "I feel foggy," "the light bothers my eyes." Dogs cannot. This means veterinary professionals must rely on observable behavioral changes, neurological examinations, and diagnostic imaging to assess brain injury severity.
Evolutionary Context: Why Dog Skulls Don't Fully Protect Their Brains
From Wolf to Pug: How Selective Breeding Changed Head Trauma Risk
The ancestral gray wolf (Canis lupus) evolved a dolichocephalic (long-skulled) head shape with substantial temporalis and masseter muscle coverage. This muscular padding, combined with a thick calvarium (skull cap) and proportionally smaller brain-to-skull ratio, provided moderate natural protection against impacts sustained during hunting — kicks from ungulate prey, collisions with terrain, and intraspecific combat.
However, approximately 10,000-15,000 years of domestication and intensive selective breeding over the last 200 years have dramatically altered canine skull morphology in ways that increase concussion vulnerability:
- Brachycephalic breeds (French Bulldogs, Pugs, Boston Terriers, Shih Tzus) have been selected for dramatically shortened skulls. Their brains are compressed into a smaller cranial vault with less cerebrospinal fluid (CSF) cushioning. A 2023 study in PLOS ONE found that brachycephalic dogs have significantly reduced subarachnoid space — the fluid-filled gap between the brain and skull that serves as the primary shock absorber.
- Toy breeds (Chihuahuas, Yorkshire Terriers, Pomeranians) have proportionally larger brains relative to skull size and thinner cranial bones, making them more susceptible to penetrating and blunt-force injuries.
- Open fontanelles: Some toy breeds, particularly Chihuahuas, may retain an open molera (persistent fontanelle — a soft spot on the skull) into adulthood, leaving a section of brain protected only by skin and thin connective tissue.
This evolutionary mismatch means that modern dogs — especially brachycephalic and toy breeds — face higher concussion risk than their wolf ancestors despite living in ostensibly safer domestic environments. The behaviors that put them at risk (darting into roads, leaping from furniture, rough play) are expressions of retained predatory motor patterns and social play drives that evolution never selected against.
Recognizing Concussion Symptoms in Dogs: A Clinical Checklist
Because dogs cannot self-report, owners and veterinarians must watch for objective behavioral and physical indicators. Symptoms may appear immediately or be delayed by hours to days.
| Severity | Symptoms | Typical Onset | Action Required |
|---|---|---|---|
| Emergency (Grade III-IV) | Loss of consciousness, seizures, unequal pupil size (anisocoria), blood from ears/nose, decerebrate rigidity (stiff extension of all limbs), coma | Immediate to 1 hour | ER vet immediately |
| Urgent (Grade II) | Disorientation (walking into walls, not recognizing owner), vomiting, nystagmus (rapid involuntary eye movement), ataxia (stumbling, inability to walk straight), extreme lethargy | 1-24 hours | Vet visit within hours |
| Monitor Closely (Grade I) | Temporary dazed appearance, slight behavior change, sleeping more than usual, reduced appetite, mild sensitivity to noise or light, appearing "off" or not themselves | 1-72 hours (often delayed) | Call vet for guidance, monitor 48-72 hours |
🚨 Go to the Emergency Vet NOW If Your Dog Shows:
- Loss of consciousness, even briefly (seconds count)
- Seizures or convulsions of any duration
- One pupil visibly larger than the other (anisocoria)
- Blood or clear fluid draining from ears or nose (may indicate skull fracture)
- Inability to stand or walk
- Abnormal eye movements (nystagmus)
- Progressive worsening of any symptom over hours
Emergency veterinary care for head trauma typically costs $500-$3,000+ for initial stabilization, diagnostics (CT scan: $1,000-$2,500), and 24-48 hour monitoring. Pet insurance with accident coverage can offset 70-90% of these costs depending on your plan.
How Veterinarians Diagnose Canine Concussions
Veterinary diagnosis of canine traumatic brain injury follows a structured protocol adapted from human Glasgow Coma Scale methodology. The American Veterinary Medical Association recognizes the Modified Small Animal Glasgow Coma Scale (MGCS), which scores three categories:
Modified Small Animal Glasgow Coma Scale (MGCS)
| Category | Score 3 (Normal) | Score 2 (Moderate) | Score 1 (Severe) |
|---|---|---|---|
| Motor Activity | Walks normally | Ataxia/paresis (weakness) | Recumbent, no response to stimuli |
| Brainstem Reflexes | Normal pupillary light reflex, normal eye movements | Sluggish pupils, reduced menace response | Absent pupillary reflexes, absent eye movements |
| Level of Consciousness | Alert, responsive | Depressed, responds to stimuli | Comatose, unresponsive |
Total score range: 3-9. Scores ≤8 indicate significant brain injury requiring intensive care. Scores ≤5 carry a guarded to poor prognosis.
Beyond the MGCS, your veterinarian may recommend:
- CT scan ($1,000-$2,500): The gold standard for identifying skull fractures, intracranial hemorrhage, and brain swelling. Faster than MRI and better for detecting acute bleeding.
- MRI ($1,500-$3,500): Superior for detecting diffuse axonal injury, subtle brain tissue damage, and edema patterns. Usually performed after the patient is stabilized.
- Blood work ($150-$350): Complete blood count and chemistry panel to assess systemic trauma, organ function, and rule out metabolic causes of neurological symptoms.
- Fundic examination ($50-$100): Ophthalmoscopic evaluation of the retina and optic nerve for papilledema (swelling), which indicates increased intracranial pressure.
Breed Variations in Concussion Risk and Recovery
Not all dogs face equal risk. Skull morphology, body size, and lifestyle factors create meaningful breed-level differences in both concussion susceptibility and outcomes.
| Breed Category | Examples | Risk Level | Why |
|---|---|---|---|
| Brachycephalic | French Bulldog, Pug, English Bulldog, Boston Terrier | High | Reduced CSF cushioning, compressed cranial vault, higher brain-to-skull ratio |
| Toy Breeds | Chihuahua, Yorkshire Terrier, Pomeranian, Papillon | High | Thin cranial bones, persistent fontanelles, low-to-ground falls can generate sufficient force relative to body mass |
| Active Sporting/Working | Labrador Retriever, German Shepherd, Belgian Malinois, Border Collie | Moderate | Higher exposure to high-velocity impacts (agility, police work, herding livestock) but better natural skull protection |
| Dolichocephalic | Greyhound, Collie, Borzoi, Saluki | Moderate-Low | More CSF cushioning, elongated skull distributes force, but thin bones in some sighthounds |
| Mesocephalic (Average) | Beagle, Cocker Spaniel, Australian Shepherd, mixed breeds | Baseline | Standard skull proportions with typical CSF buffering |
Sighthounds deserve special mention. Greyhounds and similar breeds have been documented in veterinary literature to have thinner calvarial bone compared to mesocephalic breeds of similar body weight. Combined with their high-speed athletic pursuits (lure coursing dogs reach 35-40 mph), this creates a scenario where impact forces can be significant despite their relatively protective skull shape.
How Canine Concussions Differ from Human Concussions
| Factor | Humans | Dogs |
|---|---|---|
| Symptom reporting | Self-reported (headache, nausea, foggy thinking, sensitivity to light/sound) | Cannot self-report; must be inferred from behavior, neurological exam, and imaging |
| Common causes | Sports collisions, falls, motor vehicle accidents, assault | Vehicle strikes, falls from heights/furniture, kicks from large animals, dog-dog collisions, blunt object strikes |
| Return-to-activity protocol | Standardized graduated return (6-stage protocol over days to weeks) | No standardized protocol; typically crate rest + leash-only for 7-14 days, then gradual reintroduction based on veterinary reassessment |
| Post-concussion syndrome | Well-documented: persistent headaches, mood changes, cognitive difficulties lasting weeks to months | Likely occurs but poorly characterized; some dogs show prolonged behavior changes (increased anxiety, altered sleep patterns, reduced trainability) that may represent an equivalent syndrome |
| Second impact syndrome risk | Well-established: a second concussion before full recovery can cause catastrophic brain swelling | Theoretically identical risk; this is why veterinary neurologists strongly recommend complete activity restriction during recovery |
| Cumulative effects | Repeated concussions linked to CTE (chronic traumatic encephalopathy) | No published research on CTE in dogs; working dogs (police, military, search-and-rescue) likely face cumulative risk but it remains unstudied |
Practical Recovery Protocol: What to Do After a Canine Head Injury
Step-by-Step Post-Concussion Care at Home
These steps apply AFTER your veterinarian has evaluated your dog and cleared them for home recovery. Always follow your vet's specific instructions.
Days 1-3: Strict Rest Phase
- Confine to a crate or small, padded room (remove sharp furniture edges)
- Dim lighting — avoid bright overhead lights and direct sunlight
- Minimize auditory stimulation (no loud TV, music, or household chaos)
- Leash-walk only for bathroom breaks, 3-5 minutes maximum
- Offer small, frequent meals (concussed dogs may have nausea; eating a large meal can trigger vomiting)
- Monitor pupil size every 4-6 hours: both pupils should be equal and responsive to light
- Log all behavior observations with timestamps in a notebook or phone app
Days 4-7: Gradual Reintroduction
- If symptoms have resolved: increase leash walks to 10-15 minutes, still no off-leash activity
- Reintroduce normal household sounds gradually
- Begin short, low-stimulation training sessions (5 minutes, simple known cues like "sit" and "down") to assess cognitive function
- Watch for signs of mental fatigue: yawning, lip-licking, turning away, slowed response to cues
Days 8-14: Return to Normal
- If your vet approves at the follow-up exam: gradually resume normal exercise
- Avoid high-impact activities (jumping, rough play, agility) for a full 14 days minimum
- Continue monitoring for subtle behavior changes — some dogs show personality shifts (increased irritability, clinginess, or withdrawal) that can persist for 4-6 weeks
Concussion Myths vs. Facts: What Dog Owners Get Wrong
| Myth | Fact |
|---|---|
| "If my dog didn't pass out, it's not a concussion." | Loss of consciousness occurs in fewer than 10% of mild concussions in both humans and dogs. Most concussions involve no loss of consciousness at all. |
| "Dogs have thicker skulls than humans, so they don't get concussions." | Canine skull thickness varies enormously by breed. While some working breeds have robust skulls, brachycephalic and toy breeds have thinner cranial bones and less CSF buffering than humans. |
| "My dog shook it off and seems fine, so there's no injury." | Delayed symptom onset is extremely common. Intracranial bleeding (subdural or epidural hematoma) can develop slowly over hours, with the dog appearing normal before rapid deterioration. This is why a veterinary exam within 24 hours of any significant head impact is critical. |
| "A dog that's wagging its tail after a head bump is fine." | Tail wagging is not a reliable indicator of neurological health. Dogs may wag their tails due to excitement at seeing their owner even while experiencing significant neurological impairment. |
| "Small bumps on the head can't cause a concussion." | Concussion is caused by brain movement within the skull, not external damage. Even a "minor" impact that doesn't break skin can generate enough rotational force to cause mTBI, especially in small breeds where the force-to-mass ratio is higher. |
| "You should keep a concussed dog awake." | This is a myth in both human and veterinary medicine. Sleep is part of the brain's natural recovery process. Your veterinarian may wake your dog periodically to assess neurological status, but preventing sleep does not aid recovery and may impede it. |
Prevention: Reducing Your Dog's Head Trauma Risk
While you cannot eliminate all risk, specific management strategies meaningfully reduce concussion likelihood:
- Vehicle safety: Use a crash-tested canine car harness (such as the Sleepypod Clickit Sport, certified by the Center for Pet Safety) or a secured crate. Unrestrained dogs in a 30 mph collision experience forces equivalent to a fall from a three-story building. Cost: $60-$120 for a certified harness.
- Fall prevention for small breeds: Install pet ramps or stairs for furniture access. A 10-pound Chihuahua jumping from a 3-foot bed experiences a deceleration force of approximately 30x their body weight on landing. Cost: $25-$60 for foam pet stairs.
- Yard and home proofing: Pad sharp table corners at dog-head height. Secure heavy objects on shelves. For dogs with seizure disorders, create a padded recovery space.
- Play management: Supervise dog-dog play, particularly between dogs of significantly different sizes. A 70-pound Labrador accidentally colliding with a 12-pound Dachshund during enthusiastic play can generate sufficient force for concussion.
- Working and sport dogs: Dogs in agility, flyball, bite sports, or police work face inherently higher impact exposure. Discuss preventive protocols with your veterinary neurologist, including baseline neurological exams and return-to-activity guidelines specific to your dog's sport.
Frequently Asked Questions
Can dogs get concussions from shaking their head?
Normal head shaking (to remove water, relieve ear itch, or during play) does not generate sufficient force to cause a concussion. However, violent, uncontrolled head shaking — particularly in large breeds — can occasionally be a symptom of a neurological problem (vestibular disease, ear infection, or brain tumor) rather than a cause of one. If your dog's head shaking is unusually forceful, persistent, or accompanied by a head tilt, consult your veterinarian.
Why do dogs seem to recover from head injuries faster than humans?
They likely don't. The perception that dogs "bounce back" is an artifact of their inability to report symptoms. Dogs are also evolutionarily adapted to mask signs of vulnerability — a trait inherited from wolves, for whom displaying weakness could mean exclusion from the pack or targeting by predators. A dog that appears recovered may still be experiencing headaches, visual disturbances, or cognitive difficulties that they simply cannot communicate.
What does it mean when my dog acts confused after hitting their head?
Post-impact confusion — walking aimlessly, not responding to their name, pressing their head against walls (head pressing), or appearing to not recognize familiar people or environments — is a strong indicator of brain dysfunction. Head pressing in particular is a red-flag symptom of increased intracranial pressure and warrants immediate emergency veterinary evaluation. Do not wait to see if it resolves on its own.
Is it normal for a dog to sleep a lot after a head bump?
Increased sleepiness can be normal in the first 24-48 hours after a mild head impact, as the brain uses sleep to facilitate repair. However, the critical distinction is between a dog who is sleeping but easily roused and responsive when awake versus a dog who is progressively harder to wake or who seems disoriented when they do wake. The latter pattern is a veterinary emergency.
How is concussion treatment different from humans?
The core principles are identical: rest, monitoring, and gradual return to activity. The differences are practical. Dogs cannot be told to avoid screens and mental stimulation the way human patients are. Instead, owners must control the environment — limiting sensory input, restricting physical activity through confinement, and preventing the dog from self-exercising. Medications used in human concussion management (like amitriptyline for post-concussion headaches) are sometimes used off-label in dogs under veterinary neurologist guidance, but many human concussion medications are not safe for canine use.
Can a dog fully recover from a concussion?
Most dogs with Grade I (mild) concussions recover fully within 2-4 weeks with appropriate rest and veterinary care. Grade II (moderate) injuries may take 4-8 weeks and can leave subtle residual deficits (slightly altered behavior, reduced stamina for complex tasks). Grade III-IV (severe) injuries carry a guarded prognosis — some dogs recover with permanent neurological deficits, while others may not survive despite aggressive treatment. Early veterinary intervention is the single most important factor in optimizing outcomes.
Sources & Further Reading
- Merck Veterinary Manual: Overview of Trauma of the Nervous System in Small Animals
- ASPCA: First Aid for Pets — Head Trauma Guidance
- Platt, S.R. & Olby, N.J. — BSAVA Manual of Canine and Feline Neurology (British Small Animal Veterinary Association)
Marcus Aldridge
All our authors care for dogs every day — read more of their work on the authors page.
