TL;DR: Seizures following a head injury are a critical emergency indicating potential brain swelling or internal bleeding; seek immediate veterinary care at a 24-hour hospital to prevent permanent damage.
What causes seizures in dogs after a head injury?
A seizure following a head injury—such as a fall, a car accident, or being struck by an object—is a clinical sign of traumatic brain injury. This occurs when the physical impact causes the brain to swell, bleed, or suffer from oxygen deprivation, which disrupts the normal electrical activity of the brain and leads to a seizure.
How urgent is it if my dog has a seizure after a head trauma?
- Seek immediate veterinary care at the nearest 24-hour emergency hospital as this is a high-priority emergency.
- Post-traumatic seizures often indicate rising intracranial pressure or internal bleeding.
- Professional stabilization and medication are required to prevent permanent neurological damage or fatality.
How can a video or photo of the seizure help with veterinary triage?
- Capture a short video or photo of your dog during or immediately after the episode if it is safe and does not delay your trip to the vet.
- Visual evidence allows the veterinarian to assess the type of seizure and the severity of the muscle contractions.
- The medical team can use the footage to evaluate your dog’s level of consciousness and prioritize your pet's care the moment you arrive at the clinic.
Clinical Context (Merck Veterinary Manual)
Following head trauma in dogs, immediate seizure management includes intravenous diazepam (0.5 mg/kg) or phenobarbital (5-15 mg/kg, given slowly). For persistent status epilepticus, a constant-rate infusion of diazepam (0.5-1 mg/kg/hr) may be used. If phenobarbital is contraindicated due to hepatic conditions, levetiracetam (40-60 mg/kg, IV, SC, or rectally) can be administered. Propofol can be given as a constant rate infusion at 0.1-0.6 mg/kg/min, potentially followed by a phenobarbital loading dose (2-4 mg/kg IV every 6 hours for four doses) if the patient is not already receiving it. Oral anticonvulsants should be resumed as soon as possible if the patient was previously on them; maintenance therapy includes phenobarbital (2-4 mg/kg, PO, bid) or potassium bromide (22-44 mg/kg given with food) to maintain serum levels.
Chapter: Neurology, Ophthalmology, Emergency, Trauma
Source: The Merck Veterinary Manual, 11th Edition (Page 1718)