You could try crossing it with a shrew, for improved growth rates and aggressive feeding.
If it works, Sparkie might be interested in stocking the hybrids.
If yours truly were involved, I would search out some better breeding stock first. Check out those huge, wide eyes in the second photo....that individual shows signs of being stunted if you ask me.
Try crossing it with a weasel, or mink. Those things are ferocious.