Corrigendum: Phenotypic characterization of idiopathic epilepsy and epilepsy of unknown cause in Irish Setters.

[This corrects the article DOI: 10.3389/fvets.2022.1066094.].

Phenotypic characterization of idiopathic epilepsy and epilepsy of unknown cause in Irish Setters.

Canine epileptic seizures are common neurological symptom presenting to veterinary practice. Idiopathic epilepsy (IE) with a suspected genetic background has been reported in several dog breeds. Although it has been reported in the Irish Setter (IS), the phenotypic characteristics have not yet been described. The aim of this study was to characterize the phenotype of IE in this breed and to trace its mode of inheritance. Owners of IS were requested to fill in a questionnaire via the Dutch Irish Setter Club concerning the epileptic seizures in their dogs. The data was assessed retrospectively using descriptive statistics. Forty-eight privately owned IS dogs fulfilling tier I criteria for IE according to the International Veterinary Epilepsy Task Force of both sexes were included in the study. The mean age of seizure onset was 41 months. Five of the dogs included in the study had an onset of seizures >6 years of age. These dogs were classified with epilepsy of unknown cause (EUC). Primary generalized tonic-clonic seizures were the most common type of seizure and were seen in almost all dogs. Cluster seizures were reported in 54% of the studied population. Most owners reported pre- (56%) and post-ictal (97%) signs in their dogs. A pedigree analysis of one subpopulation was performed and traced the lineage of 13 affected IS. A segregation analysis of this population rejected a simple autosomal recessive inheritance pattern. The present study supports the occurrence of IE and EUC in the IS. The results provide clinical insight into epileptic seizures in this breed and may be a starting point for further, including genetic, analysis.

Focal epilepsy with fear-related behavior as primary presentation in Boerboel dogs.

BACKGROUND: Focal seizures with fear as a primary ictal manifestation, their diagnostic challenges, and impact on quality of life are well described in human medicine. Reports focusing on ictal fear-like behavior in animals are scarce. OBJECTIVE: To describe the clinical and histopathological characteristics of a novel focal epilepsy in Boerboel dogs. ANIMALS: Five client-owned Boerboel littermates presented for evaluation of sudden episodes of severe fear-related behavior. METHODS: Clinical examination, complete blood cell count, routine blood biochemistry, and urinalysis were performed in all dogs. Magnetic resonance imaging (MRI) scans of the brain were performed in 3 affected Boerboels. In addition, in 2 affected Boerboels, metabolic screening, cerebrospinal fluid (CSF) analysis, and necropsy were performed. RESULTS: Onset of signs was 3 months of age in all affected Boerboels. All Boerboels howled loudly, had an extremely fearful facial expression and trembled during seizures. All affected Boerboels also had autonomic or motor signs. Results of laboratory investigations, diagnostic imaging, and metabolic screening were generally unremarkable. Histopathology showed moderate numbers of single large vacuoles in the perikaryon of neurons throughout the brain, specifically in the deeper cerebral cortical regions. Family history, pedigree analysis, and the homogenous phenotype were suggestive of autosomal recessive inheritance. CONCLUSIONS AND CLINICAL IMPORTANCE: The observed paroxysmal fear-related behavior represents a newly recognized hereditary focal epilepsy in dogs with distinctive clinical and histopathologic features. Veterinarians should be aware that sudden episodes of unusual behavior can represent focal epilepsy.

Reference genes for reverse transcription quantitative PCR in canine brain tissue.

BACKGROUND: In the last decade canine models have been used extensively to study genetic causes of neurological disorders such as epilepsy and Alzheimer's disease and unravel their pathophysiological pathways. Reverse transcription quantitative polymerase chain reaction is a sensitive and inexpensive method to study expression levels of genes involved in disease processes. Accurate normalisation with stably expressed so-called reference genes is crucial for reliable expression analysis. RESULTS: Following the minimum information for publication of quantitative real-time PCR experiments precise guidelines, the expression of ten frequently used reference genes, namely YWHAZ, HMBS, B2M, SDHA, GAPDH, HPRT, RPL13A, RPS5, RPS19 and GUSB was evaluated in seven brain regions (frontal lobe, parietal lobe, occipital lobe, temporal lobe, thalamus, hippocampus and cerebellum) and whole brain of healthy dogs. The stability of expression varied between different brain areas. Using the GeNorm and Normfinder software HMBS, GAPDH and HPRT were the most reliable reference genes for whole brain. Furthermore based on GeNorm calculations it was concluded that as little as two to three reference genes are sufficient to obtain reliable normalisation, irrespective the brain area. CONCLUSIONS: Our results amend/extend the limited previously published data on canine brain reference genes. Despite the excellent expression stability of HMBS, GAPDH and HRPT, the evaluation of expression stability of reference genes must be a standard and integral part of experimental design and subsequent data analysis.