This second paper is called The Effect of Dietary Protein on Liver Injury in Weanling Rats, and indeed, it shows that rats on low - protein diets experience much more actual liver damage than rats on high - protein diets when they're exposed to aflatoxin. (deniseminger.com)
This would also explain the case of weanling rats successfully blocking aflatoxin initiation fed 20 % protein, they were being fed an adequate amount of protein for their age, and hence were better at fighting off disease than their protein - starved counterparts. (westonaprice.org)
Another organism, Lawsonia intracellularis, was isolated in the mid 1980s from weanling ferrets with intestinal inflammation - and once from a pet ferret in 1989. (2ndchance.info)