ok rox
*puts on flame proof suit*
have always used Pedigree Pal and seen no adverse effects.
also use the pal tins which i have seen some adverse effects
with the chicken loaves/casseroles bobbi's stool changes color to the color of the yellow holden sorry i can't define it (i think it looks like scour)
additionally i add lamb bones, chicken peices (necks, wings, carcasses) for filler and as entertainment. this is because if the bone is too large bobbi wont eat it - she buries it about 8inches below ground level and i hate the large holes lol
hope this helps
regards
phil