Seizure control was associated with age at seizure onset (older age with better seizure control) and coat colour (merle dogs with better seizure control) but appeared unrelated to the ABCB1 (MDR1) genotype (when interpreting the latter finding, it needs to be considered that out of all the epilepsy cases  only one dog was determined to be homozygous for the ABCB1-1Δ mutation)  [9]. Here, ABCB1 is linked to epilepsy.