Paroxysmal dyskinesia (PD) is an underrecognized canine movement disorder often misdiagnosed as epilepsy due to overlapping clinical presentations. Unlike during seizures, dogs remain conscious during PD episodes. Although PD may be inherited or acquired, a subset of patients are gluten-sensitive and respond well to dietary modification (i.e., gluten-free diets). This article presents 2 cases of dogs with diet-responsive PD, which showed marked improvement or complete resolution of clinical signs after transition to a gluten-free diet, highlighting the value of considering dietary intervention in the standard of care for patients with PD. Early recognition and nutritional management may improve patient outcomes, reduce caregiver burden, and decrease the risk for unnecessary pharmacologic treatment or euthanasia.<\/p>\n
Take-Home Points<\/strong><\/p>\n <\/div><\/div><\/p>\n Nutrition and neurology are 2 fields of veterinary medicine that are not often considered together. Although awareness of the interconnectedness of nutrition and several aspects of veterinary medicine is increasing, the role of nutrition can be overlooked, especially when managing dogs with neurologic conditions such as seizures or tremors. Although diet is not typically considered a first-line therapy for neurologic conditions, paroxysmal dyskinesia (PD) offers a unique opportunity for dietary modification, which can be an effective primary treatment strategy.<\/p>\n Movement disorders are characterized by involuntary movements without changes in consciousness and can be divided into 2 categories: hyperkinetic and hypokinetic. Hyperkinetic disorders can be further classified as dyskinesia, involuntary active movements, or dystonia (sustained muscle contractions).1<\/sup> Dyskinesia<\/i> is defined as self-limiting, episodic, involuntary movements in animals.1<\/sup> Dyskinesia and dystonia occur without changes in consciousness. In dogs, distinguishing dyskinesia from hypermetria (excessive flexion of limb joints during voluntary movement) can be difficult.<\/p>\n Canine PD is a subtype of movement disorders that involves recurrent episodes of abnormal, involuntary movement. Voluntary movements, such as walking, are often impaired during episodes and may be overridden by involuntary movements. Episodes often occur spontaneously at rest but can be triggered by sudden movement. A paroxysmal exertion-induced dyskinesia is recognized in humans; however, this syndrome has not been reported in veterinary medicine.1<\/sup> Of the movement disorders in dogs, PD is among the more difficult neurologic conditions to identify, in part because diagnosis is made by observing an episode.1<\/sup> The episodes can vary in frequency and are at risk for being underdiagnosed or misdiagnosed as focal seizures because the veterinarian may not be able to witness the episode. The popularity of smartphones has increased awareness of these conditions as they enable clients to record an episode and share it with their veterinarians. Observing episodes in real time has allowed greater recognition of these conditions.<\/p>\n Unlike dogs experiencing seizures, dogs with PD remain conscious during episodes, display no autonomic signs, and do not experience a pre- or postictal phase. PD can be classified as inherited or acquired, the preferred terminology over primary or secondary. 1<\/sup> Acquired PD can result from medications (e.g., propofol, phenobarbital), intracranial structural lesions, or gluten sensitivities.1<\/sup> Regardless of whether PD is acquired or inherited, dietary modification should be considered part of the therapeutic strategy for affected patients.<\/p>\n Paroxysmal gluten-sensitive dyskinesia (PGSD), often referred to as Spike\u2019s disease (BOX 1<\/b><\/span>) among dog owners, is a condition in which a dog experiences sudden, temporary episodes of abnormal movement, such as shaking, stiffness, or difficulty walking; lip licking is also commonly seen. A feature of PD is that there is no loss of consciousness during the episode. The dogs typically appear completely normal between episodes, showing no signs of neurologic impairment.2<\/sup> Although the border terrier is the only breed in which gluten intolerance has been documented, dogs of other breeds may also show clinical improvement while being fed a gluten-free diet.3,4 <\/sup>The mechanism by which gluten causes the abnormal movements, however, is still not fully understood.<\/p>\n <\/div><\/div>\n Gluten may be present in the diet through inclusion of gluten-containing carbohydrates; however, cross-contamination during processing is also possible. Because the pet food industry does not routinely test for gluten, definitively ruling out gluten sensitivity, even when feeding a diet that does not list gluten-containing ingredients, can be difficult. One report from Italy concluded that risk for gluten contamination in pet food was minimal5<\/sup>; however, it is unknown whether the same is true for commercial pet food products in North America. According to multiple studies that have demonstrated the presence of undeclared protein sources in over-the-counter (OTC) products, OTC dry and canned diets are likely at risk for gluten cross contamination.6,7<\/sup> Many of the therapeutic diets used for allergies do not use any gluten-containing ingredients; these diets are usually the first to go through the processing line, which makes cross contamination (from gluten or another protein source) less likely. The therapeutic novel protein diets are checked for contamination of other animal sources after processing, which also makes gluten cross contamination less likely. The risk for cross contamination in fresh-style diets has not been well characterized; however, based on oral communication with 2\u00a0companies that produce this type of diet, gluten contamination seems to be lower due to their manufacturing processes (K. German, DVM, June 2025). To determine if a diet is appropriate for pets with gluten sensitivity, veterinarians and pet owners alike should contact individual companies to ask if gluten testing is performed in addition to that company\u2019s manufacturing and quality control protocols.<\/p>\n One study of PGSD (referred to as epileptoid cramping syndrome at the time of the study) in border terriers showed that all affected dogs had elevated levels of antibodies to gluten proteins, which lowered over 9\u00a0months while the dogs were fed gluten-free diets.8<\/sup> Sixty percent of the dogs were reported to have clinically improved immediately after the diet change, and the others improved after 1 month. The 1 dog that did not respond to the diet change was found to be sneaking food from another source; after that behavior was eliminated, the dog showed the same improvements. The study was conducted in Europe, where gluten antibody testing is commercially available. In the United States, however, gluten antibody testing is not commercially available. In a recent study based in Germany, researchers observed a strong improvement in signs for 64% of dogs and a partial response to diet for 14%.3<\/sup> Those results support the consideration of dietary modification, including gluten elimination, as a primary treatment strategy for select cases of canine PD.<\/p>\n No discussion of diet trials would be complete without addressing the role of treats. In the authors’ experience, client compliance is highest if clients are given specific treat replacement options rather than instruction to eliminate treats altogether. In cases of suspected PGSD, the safest treat options during the diet trial are fruits and vegetables as well as homemade dehydrated meats (without seasonings) as these items pose minimal cross-contamination risks. Commercial limited-ingredient treats may be introduced after the initial month-long diet trial; however, the potential for cross contamination during manufacturing can complicate interpretation if the dietary response is incomplete.<\/p>\n Other pets in the house should also be considered. Patients with PD are reported to be extremely sensitive to any reintroduction of gluten.8<\/sup> Dogs with PD should not be given access to other pets\u2019 food and water bowls if the other pets are eating food that is not gluten-free. Alternatively, if medically appropriate, feeding all pets in the household a gluten-free diet may help reduce the risk for inadvertent exposure.<\/p>\n Many dogs with PD will respond favorably to gluten-free diets. Home-prepared diets would have the least chance of gluten cross contamination; however, therapeutic limited-ingredient diets and many of the fresh-style diets offer gluten-free options. Clinically, most dogs show improvement within 1 month, but it can take 9 months for their antigliadin antibodies to drop to within reference range.8<\/sup><\/p>\n Although there is no direct evidence supporting the use of medium-chain triglycerides (MCTs) in dogs with PD, MCTs have shown benefits in patients with other neurologic conditions and may be considered as a potential adjunctive dietary strategy.9-11<\/sup><\/p>\n There is no direct evidence supporting the use of omega-3 fatty acids, eicosapentaenoic\u00a0acid (EPA)\u00a0and\u00a0docosahexaenoic\u00a0acid (DHA) specifically, for PD; however, their well-documented anti-inflammatory and membrane-stabilizing properties in other neurologic conditions support their consideration as adjunctive therapy in affected patients.12-15<\/sup><\/p>\n The following 2 patients with PD were referred to the veterinary nutrition service and responded well to gluten-free diets (BOX 2<\/b><\/span>).<\/p>\n Gluten-Free Grains <\/strong><\/p>\n *Oats are naturally gluten free but should be considered contaminated due to processing, unless specifically labeled as gluten free.16<\/sup><\/p>\n <\/div><\/div>\n Charlie is a 5-year-old Havanese dog with a 2-month history of seizure-like episodes (VIDEO 1<\/b><\/span>). During episodes, Charlie\u2019s thoracic limbs were primarily affected, but his pelvic limbs were occasionally affected and he also would lick his lips. During episodes, he was unable to walk but remained aware and responsive. He experienced multiple episodes per day, each lasting up to 5 minutes.<\/p>\n\n
Paroxysmal Dyskinesia<\/span><\/h2>\n
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Feeding Tips<\/span><\/h2>\n
Nutrients of Concern for Patients With Paroxysmal Dyskinesia<\/span><\/h2>\n
Gluten-Free Diet<\/h3>\n
Medium-Chain Triglycerides<\/h3>\n
Omega-3 Fatty Acids (EPA and DHA)<\/h3>\n
Case Reports<\/span><\/h2>\n
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Patient 1<\/h3>\n