Phenotypic characterisation, quality of life and prevalence of idiopathic epilepsy and epilepsy of unknown cause in the nine Dutch dog breeds.

Introduction: Canine epilepsy is a common and complex neurological disease that occurs in almost all dogs. In the Netherlands, there are nine pedigree dog breeds, and all of them have numerous small populations, with moderate to high inbreeding coefficients. The goal of this study is to characterise epilepsy within these breeds and to estimate the prevalence for each of these nine breeds: Dutch Partridge dog, three variants of the Dutch Shepherd, Dutch Smoushound, Kooiker dog, Markiesje dog, Saarloos Wolfdog, Schapendoes dog, Stabyhoun, and Wetterhoun. Method: An online questionnaire was distributed to establish the phenotypic characterisation of idiopathic epilepsy (IE) and epilepsy of unknown cause (EUC). The prevalence was estimated using data from breeders' associations, as well as cases seen by the investigators but unknown to the breed clubs. Results: The estimated prevalence of IE and EUC was for the Dutch Partridge dog 2.63%, short haired Dutch Shepherd 0.72%, rough haired Dutch Shepherd 1.21%, long haired Dutch Shepherd 0.42%, the Dutch Smoushound 2.22%, Kooiker dog 0.4%, Markiesje dog 0.84%, Saarloos Wolfdog 1.9%, Schapendoes dog 0.23%, Stabyhoun 1.5%, and Wetterhoun 2.8%. All breed clubs use breeding advice to reduce the frequency of IE/EUC, and within the Dutch Shepherd shorthaired, Kooiker dog, Smoushound, and Saarloos Wolfdog, the frequency has dropped over the years. Within all breeds, generalised tonic-clonic seizures (GTCS) were the most frequently observed type of seizures next to cluster seizures (CS) and status epilepticus (SE). Roughly, pre-ictal and post-ictal signs could be observed in half of all epileptic dogs. Anti-seizure medication (ASM) was administered to 78% of the dogs, and 70% of those experienced side effects. Only in the Wetterhoun was the need for an anti-seizure medication (ASM) less. Less than 50% of the Wetterhouns needed an ASM. The most common ASM across all breeds was phenobarbital (PB). Conclusion: Prevalence varied across the nine breeds, regardless of their population size. The phenotypic characteristics of IE/EUC are comparable with those of other dog breeds. Breeding strategy appeared to be the most effective in the Dutch Smoushound and Kooiker dog.