A cat with a concussion will typically show some combination of disorientation, unsteady walking, unequal pupil sizes, or unusual eye movements. These signs can appear immediately after a head injury or develop gradually over 24 to 48 hours, which is why close observation matters even if your cat initially seems fine.
Physical Signs to Watch For
The most reliable physical indicators of a concussion involve your cat’s eyes, movement, and coordination. Check your cat’s pupils: if one pupil is noticeably larger than the other, or if neither pupil shrinks when you shine a light toward the eyes, that signals a brain injury. Rapid, uncontrolled eye movements (where the eyes flick back and forth or up and down on their own) are another strong indicator.
Watch how your cat walks. A concussed cat often stumbles, veers to one side, or circles repeatedly in one direction. You may notice a head tilt that wasn’t there before, or your cat may struggle to stand at all. Vomiting after a head impact is common and worth taking seriously. Bleeding from the nose or ears, even if minor, points to trauma that may have reached the brain.
In more severe cases, a cat may hold its limbs unnaturally stiff and straight, with the head pulled back and neck arched. This rigid posture indicates serious brain involvement and requires immediate veterinary care.
Behavioral Changes That Signal a Problem
Concussions don’t always produce dramatic physical symptoms. Sometimes the clearest signs are behavioral. A cat that was social and responsive may suddenly seem confused, fail to recognize you, or stare blankly. Pacing or wandering aimlessly through the house, especially in patterns your cat has never shown before, can indicate injury to the front part of the brain.
Loss of consciousness, even briefly, is an obvious red flag, but subtler changes matter too. Unusual drowsiness, lack of interest in food, sudden aggression in a normally gentle cat, or a complete loss of the sense of smell can all follow a head injury. Any behavior you’d describe as “not like my cat” after a known or suspected impact to the head is worth treating as a potential concussion symptom.
One crucial detail: some brain injuries don’t show symptoms right away. Damage can remain hidden for 24 to 48 hours after the initial injury. If your cat took a fall, was hit by a car, or had any significant blow to the head, monitor closely for two full days even if everything looks normal at first.
Why Quick Action Matters
The initial impact is only part of the problem. After a head injury, swelling, reduced blood flow, and fluid buildup inside the skull can cause what veterinarians call “secondary injury,” additional brain damage that develops in the hours and days following the original trauma. The longer a concussed cat goes without treatment, the greater the risk of this secondary damage compounding the original injury.
Seizures are one of the most serious complications. A study of 332 cats with traumatic brain injuries found that about 5% developed recurring seizures afterward. Half of those cats seized immediately after the injury, but some didn’t have their first seizure until a week or more later. This delayed onset is another reason veterinary evaluation matters even when early signs seem mild.
What a Vet Exam Looks Like
Veterinarians assess brain injuries using a structured neurological exam that tests reflexes, muscle control, posture, gait, and cranial nerve function. They’ll check how your cat responds to stimulation, whether it can walk in a straight line, and how the pupils react to light. These tests help pinpoint where in the brain the injury occurred and how severe it is.
Vets use a scoring system called the modified Glasgow Coma Scale, which rates motor activity, brainstem reflexes, and level of consciousness on a scale from 3 to 18. Scores between 15 and 18 suggest a good prognosis, while scores of 8 or lower are associated with only a 50% survival rate. Each one-point increase in the score roughly doubles the odds of survival, so even small improvements during monitoring carry real significance.
If the vet suspects bleeding, swelling, or a fracture, imaging with a CT scan or MRI can reveal what’s happening inside the skull. Analysis of the fluid surrounding the brain and spinal cord can also help identify internal bleeding or infection. An EEG, which measures electrical activity in the brain, is sometimes used to detect abnormalities from head injuries.
What to Do Before You Reach the Vet
Keep your cat as calm and still as possible. Avoid letting it jump, climb, or move around more than necessary. If your cat is unconscious or semi-conscious, try to keep its head slightly elevated and avoid putting pressure on the head or neck while transporting it. Use a firm, flat surface like a cutting board or a piece of cardboard as an improvised stretcher if your cat can’t walk.
Don’t give your cat any medications unless a vet instructs you to. Don’t try to force food or water, especially if your cat is disoriented or vomiting, as this creates a choking risk. Your primary job is to minimize movement and get to a veterinary clinic as quickly as possible.
Recovery Timeline
Cats with mild concussions may begin showing improvement within a few days, but a full recovery often takes about a week. During this time, most cats are kept at the veterinary clinic for monitoring, since the risk of secondary brain injury and delayed seizures makes home observation risky in the early stages. Body temperature regulation can be disrupted after brain trauma, causing fever or abnormally low body temperature, and heart rate may slow significantly. These are things that need professional monitoring.
Once a cat is stable enough to come home, expect a gradual return to normal behavior rather than an overnight recovery. Some cats regain full function quickly, while others take weeks. Cats that experienced seizures, prolonged unconsciousness, or severe coordination problems may have longer recovery periods or lasting neurological effects. Your vet will likely schedule follow-up exams to track your cat’s progress and catch any late-developing complications.