When Gastrointestinal Episodes are Actually Seizures: Recognizing Focal Autonomic Seizures in Dogs

A dog has recurrent episodes of ptyalism, vomiting, abdominal discomfort, or other digestive signs. Gastrointestinal investigations have not identified a clear cause, and repeated treatment for gastroenteritis provides little improvement. Could the episodes be neurological rather than gastrointestinal? 

Focal autonomic seizures can present predominantly with digestive and other autonomic signs, making them particularly difficult to recognize. In human medicine, reported autonomic manifestations include retching, ptyalism, nausea, vomiting, abdominal discomfort, borborygmia, diarrhoea, tachycardia, bradycardia, and changes in pupil size^[1],[2]. 

When Should Seizures Enter the Differential?^[2] 

The pattern of the episodes is an important clue. 

Focal autonomic seizures should be considered in dogs with recurrent, paroxysmal digestive episodes, particularly when an extensive gastrointestinal work-up has failed to identify a causative disease or when there is a poor response to chronic gastroenteritis treatment. 

Ptyalism may be especially prominent. However, excessive salivation does not necessarily indicate primary salivary gland disease. In this case series, all dogs exhibited ictal ptyalism, but only one had enlarged salivary glands. 

The absence of obvious neurological signs between episodes should not necessarily exclude a seizure disorder. During the interictal period, these dogs had normal neurological examinations. 

Look for Clues Beyond the Gut^[2] 

Does the dog show altered awareness during an episode? Are there behavioural changes, repetitive movements, or other seizure manifestations? 

These findings can strengthen suspicion of an epileptic event. One dog in the series experienced generalized tonic–clonic seizures in addition to focal autonomic seizures. Another exhibited behavioural seizures with impaired awareness, chewing, and paw licking. 

However, another dog showed only autonomic seizure manifestations. Therefore, the absence of another recognizable seizure type should not definitively rule out an epileptic origin. 

Pre- and postictal changes may also help classify a paroxysmal event as a seizure, but they are not consistently present in focal autonomic seizures. Only one dog in the series exhibited a postictal phase. 

What About Episodes Lasting for Hours? 

Prolonged episodes can create another diagnostic dilemma. Seizures typically last less than 5 minutes, with longer events classified as status epilepticus. However, focal status epilepticus can occur in certain human epilepsy syndromes. In self-limited epilepsy with autonomic seizures (SeLEAS), 44% of seizures are reported to last more than 10 minutes and may persist for hours^[3]. 

The dogs in this case series also had prolonged clinical signs, often lasting for hours. Therefore, unusually long episodes should not automatically steer the clinician away from seizures when the rest of the clinical picture is compatible. 

Where Does EEG Fit? 

When focal autonomic seizures are suspected, EEG can help distinguish epileptic from non-epileptic events. Ictal or interictal abnormalities supported the diagnosis in these dogs, together with an initial reduction of more than 50% in seizure frequency following treatment. 

A normal routine EEG does not necessarily exclude the diagnosis. In SeLEAS, ictal abnormalities can be identified in up to 90% of patients, and sleep EEG may be useful when routine EEG is normal^[2],[4]. Prolonged video-EEG monitoring increases the likelihood of capturing spontaneous seizures, with a minimum of 24 hours considered the gold standard^[5],[6]. 

Clinical Bottom Line 

For dogs with recurrent unexplained digestive episodes, especially when gastrointestinal investigations are unrewarding and response to chronic gastroenteritis treatment is poor; focal autonomic seizures belong in the differential diagnosis. 

Ptyalism, altered awareness, other seizure manifestations, prolonged paroxysmal episodes, EEG abnormalities, and treatment response can help build the case. The key is to recognize that a seizure does not always look like a classic generalized convulsion; it may present primarily as a recurring gastrointestinal problem.

References:

1. Moseley B, Bateman L, Millichap JJ, Wirrell E, Panayiotopoulos CP. Autonomic epileptic seizures, autonomic effects of seizures, and SUDEP. Epilepsy & Behavior. 2013 Mar 1;26(3):375-85. https://www.academia.edu/download/41830259/Autonomic_epileptic_seizures_autonomic_e20160131-27253-1jr8no0.pdf
2. Diop S, Lyon E, Van Caenegem N, Escriou C, Freiche V, Blot S. Focal Autonomic Seizures Manifesting With Prevailing Signs of Gastrointestinal Disorder in Dogs. Journal of Veterinary Internal Medicine. 2025 Jul;39(4):jvim70158. https://academic.oup.com/jvim/article-pdf/39/4/jvim70158/67010597/jvim70158.pdf
3. Dobesberger J, Ristić AJ, Walser G, Kuchukhidze G, Unterberger I, Höfler J, Amann E, Trinka E. Duration of focal complex, secondarily generalized tonic–clonic, and primarily generalized tonic–clonic seizures—A video-EEG analysis. Epilepsy & Behavior. 2015 Aug 1;49:111-7. https://www.academia.edu/download/43712648/Duration_of_focal_complex_secondarily_ge20160314-14055-1dghods.pdf
4. Graziosi A, Pellegrino N, Di Stefano V, Raucci U, Luchetti A, Parisi P. Misdiagnosis and pitfalls in Panayiotopoulos syndrome. Epilepsy & behavior. 2019 Sep 1;98:124-8. https://www.academia.edu/download/118948402/j.yebeh.2019.07.01620241016-1-vzxs18.pdf
5. Timpte K, Rosenkötter U, Honrath P, Weber Y, Wolking S, Heckelmann J. Assessing 72 h vs. 24 h of long-term video-EEG monitoring to confirm the diagnosis of epilepsy: a retrospective observational study. Frontiers in neurology. 2023 Oct 20;14:1281652. https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1281652/full
6. Folkard E, Niel L, Gaitero L, James FM. Tools and techniques for classifying behaviours in canine epilepsy. Frontiers in Veterinary Science. 2023 Nov 1;10:1211515. https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1211515/pdf