5 Aug 2025
Lauren Demos BVSc, BVMS(Hons), DABVP(Feline), MRCVS looks at what can be done for cats with this distressing condition and the choices available, including more holistic approaches
Lauren Demos
Job Title
Image: Evrymmnt/ Adobe Stock
Seizures, in general, are notably one of the more distressing conditions for pet owners to witness. Both their unpredictable nature, along with the emotional stress that can result from observing a pet’s seizure activity (often in a home environment distanced from medical care), can result in a particularly unpleasant experience. This is in spite of the fact that, clinically, seizures themselves are uncommonly life threatening.
The term “seizure” is often used to describe any sudden, short-lasting and transient neurological event; an epileptic seizure is the manifestation of excessive synchronous, usually self-limiting, epileptic activity of neurons in the brain, resulting in clinical signs that can include generalised convulsions or focal motor, autonomic or behavioural features1.
The condition of epilepsy is, therefore, defined as a disease of the brain characterised by an enduring predisposition to generate epileptic seizures; practically, this is usually meant to be at least two unprovoked epileptic seizures more than 24 hours apart2.
While a paucity of data exists for feline epilepsy compared to canine epilepsy, some authors report the prevalence in a feline referral patient population to range from 0.5% to 3.5%3,4. Due to the inherent difficulty in observing the act of epilepsy in a clinical setting (and similarly recording such events in the home environment), as well as the confusion that has been perpetuated around terminology, epilepsy presents unique challenges in diagnosis, treatment and management, regardless of the species.
This review explores feline epilepsy, in particular the treatment and management options therein.
The diagnosis and, therefore, treatment of feline epilepsy often relies on owners’ observations, descriptions and/or recordings of events, which is known as seizure semiology: the detailed observations of physical signs during a seizure episode indicative of an alteration in neurological state5.
Seizure semiology is, therefore, a critical component of understanding, defining and diagnosing seizures in companion animals. Arguably, inaccurate descriptions or vague terminology can hinder the diagnostic process. These challenges are not limited solely to laypersons: inter-observer variability has been recorded in veterinary professionals viewing the same footage provided by owners of potential seizures in their pets, highlighting the difficulties that epilepsy presents in veterinary patients and the need to formulate the diagnosis through an amalgamation of clinical signs, signalment and history, aided by various diagnostics5.
In human medicine, epilepsy and seizures have been governed by very specific terminology since 1964 by the International League Against Epilepsy, ensuring a common linguistic framework exists.
No such universal framework existed in veterinary medicine until recently, though attempts have been made, which has led to inherently ambiguous and potentially stigmatising terminology, in addition to creating potential confusion in the scientific literature. More recently, the International Veterinary Epilepsy Task Force has attempted to correct this deficiency2.
In practice, many clinicians still utilise an aetiological classification system for feline epilepsy.
Categories often include the following:
Epileptic seizures are generally characterised by four stages: prodrome, aura, ictus and postictal, with the prodrome being the least consistent stage and often overlooked by cat owners. Prodrome precedes the seizure onset and can last for seconds to days, though in most instances it tends towards shorter periods.
Without EEG testing in animals, it is impossible to differentiate aura from prodrome, whereas in humans, it is defined as the subjective feeling of an initial ictal event. Ictus represents the seizure itself and usually lasts no longer than a few minutes.
Clinical signs of ictus can include drooling, twitching, tremoring, running, mydriasis, hypersalivation, urination or defecation. This is followed by the postictal stage; in cats, clinical signs of this stage can include aggression, polyphagia, polydipsia, loss of hearing or vision, and ataxia. Seizures can be focal or generalised, and both can occur in the same patient.
Differential diagnoses can encompass a wide range of conditions, including behavioural changes, obsessive compulsive disorders, sleep disorders (and normal dreaming), pain-associated behaviour, syncope, feline orofacial pain syndrome, vestibular disease, neuromuscular disease and encephalopathies.
Management of feline epilepsy poses distinct challenges for veterinarians. Varying aetiologies, as well as differing individual responses to management therapies, can lead to high variation in clinical outcomes and decisions.
Antiepileptic drugs (AEDs) have become a first-line therapy for feline epilepsy, with phenobarbital currently considered the first line choice by many practitioners, followed by levetiracetam and imepitoin6.
Feline epileptic patients are often treated with different AEDs than other species, and it is often accepted that the effectiveness of an antiepileptic drug may outweigh its adverse effects7. However, it is essential that clinicians evaluate the effectiveness and tolerability of any AED therapy instituted, and consider individual patient responses, rather than making blanket treatment assumptions.
Phenobarbital can be used as a monotherapy or in combination with other AEDs. One retrospective evaluation of eight studies totalling 137 cats found that the majority of the study populations were treated successfully with phenobarbital6.
The authors also profiled 12 additional studies evaluating the safety profile of the drug, with a sample size of 147 cats; while the majority of the sample population did not show adverse effects, the most common included sedation6. Other less common adverse effects included behavioural changes, pruritus, thrombocytopenia, stomatitis, coagulopathy, polyphagia, polydipsia and weight loss. Adverse effects did not follow a dose or serum level dependent pattern6.
Phenobarbital generally reaches steady state serum concentrations within two to three weeks after starting the medication or dose changes, therefore levels are generally tested within this time frame. Timing of sample collection is not considered critical, as the dosing interval is shorter than the drug half life. Cats infrequently require the same increasing dose adjustments as canines, due to differences in hepatic microsomal enzyme activity.
Levetiracetam can be used as a monotherapy agent or in combination with phenobarbital. A retrospective evaluation of studies reviewed the cases of 43 cats and found that the majority of the study population treated with levetiracetam, either as a monotherapy or as a combination therapy, were treated successfully6.
In the same publication, studies were retrospectively analysed for adverse effects reported across a total of 67 cats. In general, the majority of cats had no adverse effects reported, but when seen, included gastrointestinal and neurological signs, along with polydipsia, and the most commonly reported, hypersalivation. Similar to phenobarbital, the reported adverse effects did not follow a dose or serum level dependent pattern.
Limited information is available in the literature regarding imepitoin for feline epilepsy. Imepitoin is a partial GABA receptor agonist developed and licensed specifically for the treatment of canine epilepsy8.
A single published study assessed the efficacy of imepitoin as a monotherapy agent in eight cats across 30 days; four achieved clinical remission during the study, while adverse events in treated cats included lethargy, decreased appetite and vomiting9.
Similarly to imepitoin, limited data is published on the use of zonisamide in cats with epilepsy. One retrospective study reported that 70% of cats (n=24) receiving it as a sole AED experienced a significant reduction in seizure frequency and severity10. Adverse effects have been reported in up to half of cats receiving the drug, and include anorexia, vomiting, diarrhoea, somnolence and ataxia11.
Various other pharmacologic agents have been used as adjunctive or first-line AEDs in cats, including potassium bromide, gabapentin, pregabalin and others. Their use and management often comes without significant data to support their effectiveness, or with potential concerns for adverse effects.
Dietary management has been studied and utilised in various other species, including ketogenic diets in humans. Building on this, a proprietary diet formulated for dogs containing medium-chain fatty acids has been more recently developed12. One recent study of dogs with AED-resistant IE found that 14% (3 of 21 dogs) became seizure free on the diet, while 48% had a more than 50% reduction in seizure frequency13.
At present, a lack of similar published studies in cats precludes similar conclusions for feline epilepsy.
Successful management of feline epilepsy may vary by individual patients and supervising clinicians, but in general can be defined as decreased seizure frequency and/or severity, along with a good quality of life.
Some authors suggest that three to four seizures a year are considered acceptable standards, though individual circumstances and clinicians preferences will vary14. If after three to four weeks of AED therapy, seizure severity and frequency have not improved, re-evaluation of potential causes and/or monitoring drug concentrations should be considered.
Adjunctive therapy may also be considered if drug concentrations are within the therapeutic range, or not responding to dose adjustments. Some clinicians will further attempt to discontinue AED therapy if no seizures have been reported for 6 to 12 months, though this practice is not followed by all clinicians14.
The prognosis for seizure control and response to therapy is ultimately dependent on the underlying aetiology. No correlation is known to exist between the severity of seizures and outcome14. In many cases, AED management can result in effective long-term seizure control, with good patient quality of life.
Feline epilepsy is, generally, a manageable condition with a variety of AED treatment options.
At present, pharmaceutical intervention remains the cornerstone of therapy; however, emerging treatments taking a more holistic approach to patient management offer exciting options for new therapies going forward.
Ongoing research into feline epilepsy will undoubtedly provide new strategies for caring for feline patients with the disease, along with their owners.
Lauren Demos graduated from Murdoch University, Australia, and completed a feline medicine residency and obtained her specialist status in 2019; subsequently, she has practised in various niches of veterinary medicine around the world. She currently is a consultant in private practice, lecturing and teaching on various feline topics, as well as consulting for various veterinary businesses and non-profit organisations. Lauren has published on various wide-ranging topics in feline medicine, such as novel research into feline papillomavirus, and co-authored Cats For Dummies. She is passionate about feline internal medicine and integrating various therapeutic approaches of feline medicine to treat the feline patient in toto.
