Sauteur d'Alfort rabbit-like locomotory disturbances and eye disorders in two pet rabbits—‘handstand rabbits’

Abstract

Homozygous sauteur d'Alfort rabbits have a splicing-site mutation in the RAR-related orphan receptor B (RORB) gene that causes changes in their locomotion. These rabbits sometimes walk on their thoracic limbs, especially at higher speeds. They also experience additional abnormalities, including eye alterations such as blindness due to retinal dysplasia, cataract formation, lens luxation, coloboma, glaucoma and other complications. This report describes two 17-month-old intact female dwarf rabbits that have exhibited locomotory disturbances since their first few weeks of life and severe eye alterations since they were several months old. Both animals appeared smaller than their other siblings. The locomotory and eye alterations resemble those observed in sauteur d'Alfort rabbits. Genetic analysis showed that both rabbits were homozygous for the wild-type mutation in the RORB gene. This indicates that their behavioural and ocular alterations were attributable to a distinct genetic basis rather than the sauteur d'Alfort allele.