High incidence of spontaneous cataracts in aging laboratory rabbits of an inbred strain.

OBJECTIVE

To investigate the occurrence of spontaneous cataracts in a breeding colony of the inbred EIII/JC strain of New Zealand White rabbits (Oryctolagus cuniculi) and the congenic strain of EIII/JC-HLA-A2.1transgenic rabbits.

PROCEDURE

A retrospective study was conducted by collecting and analyzing data from clinical records for individual rabbits filed between January 2011 and October 2013.

RESULTS

Thirteen cases (eight females and five males) of cataract were identified in a group of 51 EIII/JC inbred rabbits with a morbidity of 25.5%. The median age of the rabbits identified with unilateral or bilateral cataracts was 43 months in contrast to the median age of 23 months of the entire group of 51 rabbits. Additionally, seven cases (five females and two males) of cataracts were identified in a group of 21 EIII/JC-HLA-A2.1 transgenic rabbits. The EIII/JC-HLA-A2.1 transgenic rabbits showed similar morbidity (33.3%) and median age (41 months) for the development of cataracts as the EIII/JC rabbits. In both groups, none of the rabbits younger than 37 months developed cataracts while 13 (93%) of 14 EIII/JC rabbits aged 37-49 months and seven (63.6%) of 11 EIII/JC-HLA-A2.1 transgenic rabbits aged 37-43 months developed cataracts. In contrast, none of 78 outbred rabbits with a median age of 26 months (10-67 months) developed cataracts.

CONCLUSION

Results of this study indicate that the occurrence and high incidence of spontaneous cataracts in this inbred strain (EIII/JC) of rabbits were strictly age related and consistently transmitted through inbreeding.