But at what point does adapting to a particular component of a diet change that component from sub-par to being considered part of the normal, healthy diet? At some point in the distant past eucalyptus leaves were probably the subpar food source, but try feeding a koala bear anything else. That's obviously an extreme example, but... the point stands. I think what this study opens the door to demonstrating is that there are probably a lot more foods that are "healthy" for dogs and they really are more generalist than many people have been previously willing to consider. What I would really, REALLY love to see someday is someone doing something similar to this but comparing different individuals to one another and trying to correlate results to those individuals' tolerance of different types of food. Hopefully it will be done in my lifetime.