Here at Movement Referrals, we’d like to introduce our new blog collection. Each one will focus on a particular condition, relating to three key areas; Orthopaedics, Neurology and Spinal Surgery, aimed at those looking for a top-up of knowledge.
Kicking off the series, we’re going to be looking at seizures. What are the causes? What are the stages? Is characterising the seizure really important? What constitutes a seizure emergency and what do you need to do next?
Most vets are confident at recognising a dog in status epilepticus; an emergency presentation that is usually dramatic, unmistakable, and understandably accompanied by very anxious owners. However, correctly interpreting these dogs who present as having “had a funny turn” can be challenging. Missing key clues may lead to inappropriate treatment, delayed diagnosis, or unnecessary use of anti-epileptic medication.
At Movement Referrals, we see dogs every week whose owners are convinced they have epilepsy, and just as often, dogs whose clinical signs turn out to be something else entirely.
As independent veterinary specialists with a strong focus on neurology, a core part of our role is helping both vets and owners recognise what a seizure really looks like, and when it is important to pause before labelling a dog as epileptic.
What causes a seizure?
A seizure occurs when there is excessive, abnormal neuronal activity within the cerebral cortex. This arises from an imbalance between excitatory and inhibitory mechanisms that normally regulate neurotransmitter release and electrical firing within the brain.
Seizure activity typically begins in a focal area of the cerebrum (the seizure focus) and may remain localised or spread to involve both cerebral hemispheres. Importantly, a seizure always indicates forebrain dysfunction – but it is not, in itself, a diagnosis.
The mechanisms that lead to seizures can be broadly divided into extracranial and intracranial causes.
Extracranial causes occur secondary to non-neurological disease.
- These are typically metabolic or toxic in origin and alter neuronal chemistry throughout the brain.
- Examples include hypoglycaemia, electrolyte disturbances, hepatic encephalopathy, or toxin exposure.
- Dogs with extracranial disease often show additional clinical signs such as vomiting, weakness, tremors, or systemic illness.
Intracranial causes involve structural or functional brain disease.
- Examples include neoplasia, inflammatory or infectious encephalitis, infarction, congenital malformations, or degenerative disease.
- Idiopathic epilepsy also falls within this category and is thought to have a genetic basis in many breeds.
Recognising the different seizure stages
A seizure event can be divided into three stages, each of which provides useful diagnostic information:
The prodromal phase: often referred to as an “aura”, occurs minutes to hours before a seizure, and in some dogs may be noted days in advance. Owners may describe behavioural changes such as anxiety, withdrawal, restlessness, attention-seeking, or vocalisation.
The ictus: the seizure itself. This is the period of abnormal neuronal activity and is where seizure type and classification are determined.
The post-ictal phase: follows the seizure and typically lasts minutes to hours. Common clinical signs include disorientation, confusion, lethargy, pacing, appetite changes, and temporary vision loss. Transient forebrain abnormalities usually resolve within 24 hours in epileptic patients.
These stages – particularly the presence of a post-ictal phase – are extremely helpful when distinguishing seizures from syncope, movement disorders, or musculoskeletal events.
Understanding what happens between episodes is just as important as the event itself.
Abnormal inter-ictal behaviour suggests ongoing forebrain dysfunction or metabolic disease. Clinical signs may include altered mentation, pacing, circling, blindness, or loss of learned behaviours.
How are seizures classified?
Once a seizure has been officially identified, the next step is to work out the type of seizure. According to International Veterinary Epilepsy Task Force guidelines, seizures are classified primarily by their onset: focal or generalised.
Focal seizures: arise from abnormal neuronal activity in a discrete region of one cerebral hemisphere. Clinical signs are often subtle and may include facial twitching, lip smacking, fly snapping, head turning, repetitive limb movements, or sudden behavioural changes such as fear or agitation. Awareness may be impaired or preserved. Focal seizures may remain localised or progress to become focal-to-generalised seizures.
Generalised seizures: involve both cerebral hemispheres from the outset. While generalised tonic–clonic seizures are the most recognisable form, they are not the only type of generalised seizure. Generalised seizures also include absence seizures, characterised by brief lapses in awareness, and myoclonic seizures, which present as sudden, brief muscle jerks.
Focusing only on generalised tonic-clonic seizures risks missing other clinically important seizure types.
Seizure-related emergencies
Seizures are rarely life-threatening when they occur as isolated, self-limiting events. However, two presentations constitute true neurological emergencies:
Cluster seizures, defined as two or more epileptic seizures occurring within a 24-hour period.
Status epilepticus, if a seizure lasts longer than five minutes, or multiple seizures occur without full recovery of consciousness between events.
Both cluster seizures and status epilepticus require urgent veterinary intervention to reduce the risk of hyperthermia, cerebral injury, and systemic complications.
Assessing seizure activity in practice
A thorough history is essential, as most patients are not actively seizuring at the time of examination unless presenting as an emergency.
Key information includes:
- Seizure frequency,
- Duration,
- Recovery characteristics,
- Demeanour between episodes,
- Age at onset,
- Previous medical history,
- Any potential toxin exposure.
Physical examination should include careful cardiovascular and musculoskeletal assessment to exclude common causes of collapse.
A detailed neurological examination is essential, including assessment of menace response, nasal sensation, and postural reactions.
A normal inter-ictal neurological examination is a criterion for idiopathic epilepsy. If abnormalities are present, asymmetrical deficits suggest intracranial disease, whereas symmetrical deficits are more consistent with metabolic or extracranial causes.
Smartphone video recordings are now one of the most valuable diagnostic tools available. Video allows assessment of awareness, movement quality, symmetry, duration, and recovery – information that is often impossible to capture accurately through verbal description alone.
How Movement Referrals can help
At Movement Referrals, our neurology specialists work closely with first-opinion practices to support the accurate diagnosis and management of dogs with suspected seizures. Our role is not only to diagnose epilepsy, but also to help identify seizure mimics, guide appropriate investigations, and ensure that anti-epileptic therapy is used appropriately and effectively.
Recognising seizure activity can be challenging, particularly when clinical signs are subtle or atypical. Taking a structured approach, combining careful history taking, neurological examination, and video assessment will greatly improve diagnostic confidence.
If you would like further advice on a specific case, contact us as our specialist team is always happy to help.