Paroxysmal Dyskinesia in Border Terriers: Clinical, Epidemiological, and Genetic Investigations

Abstract

BackgroundIn the last decade, a disorder characterized by episodes of involuntary movements and dystonia has been recognized in Border Terriers.ObjectivesTo define clinical features of paroxysmal dyskinesia (PD) in a large number of Border Terriers and to study the genetics of the disease.Animals110 affected and 128 unaffected client‐owned Border Terriers.MethodsA questionnaire regarding clinical characteristics of PD was designed at Utrecht University and the University of Helsinki. Thirty‐five affected Border Terriers underwent physical examination and blood testing (hematology and clinical biochemistry). Diagnostic imaging of the brain was performed in 17 affected dogs and electroencephalograms (EEG) between episodes were obtained in 10 affected dogs. A genomewide association study (GWAS) was performed with DNA of 110 affected and 128 unaffected dogs.ResultsOne hundred forty‐seven questionnaires were included in the study. The most characteristic signs during episodes were dystonia, muscle fasciculations, and falling over. The majority of owners believed that their dogs remained conscious during the episodes. A beneficial effect of anti‐epileptic therapy was observed in 29 of 43 dogs. Fifteen owners changed their dogs’ diet to a hypoallergenic, gluten‐free diet, and all reported reasonable to good improvement of signs. Clinical examinations and diagnostic test results were unremarkable. The GWAS did not identify significantly associated chromosome regions.Conclusions and Clinical ImportanceThe survey results and EEG studies provided further evidence that the observed syndrome is a PD rather than epilepsy. Failure to achieve conclusive results by GWAS indicates that inheritance of PD in Border Terriers probably is complex.

A multicenter randomized controlled trial of medium‐chain triglyceride dietary supplementation on epilepsy in dogs

“…The influence of dietary modification on seizure control has been extensively studied in human medicine 26‐29 and rodent epilepsy models, 30‐33 showing antiseizure effects to varying degrees. Similarly, there are effects of nutritional management and diets in dogs with epilepsy 23,24,34‐39 and paroxysmal dyskinesia 40‐43 …”

Levetiracetam‐responsive paroxysmal exertional dyskinesia in a Welsh Terrier

“…Paroxysmal dyskinesia in Border Terriers is also characterized by recurrent episodes of abnormal involuntary muscle movements, with no loss of consciousness. 31,32,57 However, the episodes were not preceded by prolonged exercise, and were triggered by waking from sleep or by excitement. Approximately 20% to 30% of affected Border Terriers display autonomic signs (borborygmi, urination, and diarrhea).…”

Approach to canine paroxysmal dyskinesias

“…An association between gluten sensitivity and this characteristic PD was demonstrated in BTs (Lowrie et al 2018;Lowrie et al 2015). Age of onset is six weeks to nine years (Black et al 2014;Lowrie et al 2018;Stassen et al 2017). Dystonia of the limbs/ head/ neck, tremors, ataxia, difficulty walking, and inability to maintain a standing position are common associated findings and are often accompanied by borborygmi (Black et al 2014;Lowrie et al 2018;Lowrie & Garosi 2017;Lowrie et al 2015;Urkasemsin & Olby 2015).…”

“…Concurrent dermatological and gastrointestinal disease is possible as seen in people with gluten sensitivity (Black et al 2014;Hadjivassiliou et al 2003;Lowrie et al 2018). No genetic mutation could be identified in a cohort of 110 dogs indicating a complex mode of inheritance (Stassen et al 2017). A link between dietary exclusion of gluten and resolution of clinical signs was shown (Lowrie et al 2015).…”