Seizure or Look-Alike? Differentiating Episodic Events in Dogs and Cats

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Canine Neurology Clinical examination Neurological Signs Seizures Feline Neurology Syncope Tremors Neurology Movement Disorders Seizure Mimics Vestibular Disease Episodic Events

Seizure or Look-Alike? Differentiating Episodic Events in Dogs and Cats

A dog suddenly collapses, paddles its limbs, and urinates. Is it a seizure?

Not necessarily.

Syncope can produce brief loss of consciousness, muscle jerks, and even urination. Similarly, vestibular episodes, tremors, and movement disorders may appear dramatic while the patient remains conscious.

For the clinician, the challenge is often not witnessing the event but reconstructing it from history, physical examination, and an owner-recorded video.

Start With What Happened During and After the Event

When a seizure is suspected, ask the owner to describe the episode rather than relying on the label “seizure.”

Useful questions include:

How long did the episode last?
How many episodes occurred?
Was the animal responsive?
Was there urination or defecation?
What was the animal doing immediately before and after the event?
How long did it take to return to normal?
Has this happened before?
Was anything suspected to trigger the episode?
Is there a video of the event?

The recovery period can be particularly useful. Generalized seizures typically have a post-ictal period with abnormal mentation or behaviour that may last from minutes to days. Focal seizures may occur without obvious post-ictal behaviour.

Clinical Features That Help Separate Seizures from Look-Alikes^[1]

Feature	Seizure	Syncope	Vestibular disease	Tremors Movement disorders
Consciousness	May be lost	Brief loss of consciousness	Usually aware and responsive	Conscious and responsive
Movement	Rhythmic focal or generalized movements	May include myoclonus or spasms	May paddle while attempting to right itself	Rhythmic tremors or involuntary contractions
Before/after event	May have pre-ictal or post-ictal changes	Usually normal before; rapid recovery afterward	Vestibular signs may persist between episodes	Neurologic examination may be normal between episodes
Other clues	Urination, defecation, salivation may occur	May urinate; often associated with exertion, excitement or coughing	Head tilt, nystagmus, postural deficits	No typical loss of consciousness

Could It Be Syncope?

Syncope results from a temporary interruption of perfusion, oxygenation or nutrient delivery to the brain. Some patients may develop myoclonus or spasms, making the episode difficult to distinguish from a generalized seizure^[2]^,[3].

The trigger may provide an important clue. Exercise, exertion, severe coughing, excitement or environmental stressors can precede syncope^[1].

The recovery pattern is also valuable. A syncopal patient generally regains normal mentation almost immediately, without a lingering post-event neurologic abnormality^[1]. Because cardiac disease is a common cause, examination may reveal arrhythmia, heart murmur, or pulse deficit.

When Balance Problems Mimic Convulsions

Vestibular episodes can be equally confusing. A severely unbalanced patient may repeatedly attempt to right itself after falling, producing limb movements that resemble seizure activity.

Look for accompanying vestibular findings: head tilt, nystagmus, strabismus, postural deficits or other cranial nerve-related neurologic abnormalities. Unlike a typical seizure, the vestibular patient remains aware and responsive to stimuli.

What About Tremors and Movement Disorders?

Tremors are rhythmic oscillations without loss of consciousness^[2]. They may result from idiopathic, toxic, or metabolic causes, including hypocalcemia.

Movement disorders involve involuntary skeletal muscle contractions in a conscious, mentally appropriate patient. Examples described in dogs include peripheral nerve hyperexcitability disorders, paroxysmal dyskinesia, and dystonia^[1]^,[4].

Clinical Bottom Line

A dramatic movement does not automatically mean seizure activity. Consciousness, responsiveness, triggers, accompanying neurologic signs, and recovery patterns can provide valuable differentiation. When the event is not witnessed in the clinic, a carefully obtained history and owner video can become central to determining whether the episode represents a seizure or a look-alike.

References:

Munguia GG, Brooks AC, Thomovsky SA, Thomovsky EJ, Rincon A, Johnson PA. Emergency approach to acute seizures in dogs and cats. Veterinary Sciences. 2024 Jun 17;11(6):277. https://www.mdpi.com/2306-7381/11/6/277
Lowrie M, Garosi L. Classification of involuntary movements in dogs: tremors and twitches. The veterinary journal. 2016 Aug 1;214:109-16. https://www.researchgate.net/profile/Mark-Lowrie/publication/303411830
Charalambous M, Gomes SA, Papageorgiou S, Orioles M. Epileptic seizures versus syncope: pathophysiology and clinical approach. Veterinary Evidence. 2017 Feb 28;2(1). https://veterinaryevidence.org/index.php/ve/article/download/58/137
Cerda-Gonzalez S, Packer RA, Garosi L, Lowrie M, Mandigers PJ, O'Brien DP, Volk HA. International veterinary canine dyskinesia task force ECVN consensus statement: terminology and classification. Journal of Veterinary Internal Medicine. 2021 May;35(3):1218-30. https://academic.oup.com/jvim/article-pdf/35/3/1218/66652662/jvim16108.pdf