The objectives of this study were to perform a genome-wide association study (GWAS) in PRT for hereditary ataxia using the canine Illumina high density bead chip and then to show whether the previously reported SCA- and LOA-associated KCNJ10 and CAPN1 genes in PRT and JRT are in windows of significantly associated genomic regions. The gene discussed is CAPN1; the disease is autosomal dominant cerebellar ataxia.