@captain alligator more than likely due to their physical similarities with the North American River Otter, which you’ve stated yourself in another post.
@captain alligator Huachipa has a breeding group, but this is the only known holder of this highly threatened species. They are Endangered and were listed under CITES Appendix I in 1976. Very hard to source from Western zoo, I believe.
@captain alligator Lack of interest and availability I would say. Most other otter species are easily more available for other zoos in the world to obtain.