I recently started using Arm & Hammer Slide litter which is very dark in color. Yes it doesn't stick to the litter box but it sticks all over my cat's paws and tracks outside the litter box badly. I noticed today that my other cat's stool was black but she's fine otherwise. I know that black stools are a sign of blood in the stool, but come to think of it Cat #1 is having darker stools also. What are the odds of that? My theory is the cats are cleaning their paws and ingesting some of the litter which may be turning their stools black/dark. Has anyone else had this experience?? I'll be keeping a close eye on things to determine if I need to bring in stool samples to their vet's clinic. Thank you for any feedback!