Concerned about my puppy's stools. (pictures included).

I am concerned about my 4.5month old puppy's stools. I do not know what the shiny black part in his stools means. Is this something I should be concerned about, or do his stools look normal ? pictures: https://imgur.com/a/RxseZgY https://imgur.com/a/8JGbYe4 https://imgur.com/a/wjiYBlg

bump

Hello and thank you for the pictures.  I have seen at least two of the photos, showing formed- looking, mottled faeces.   I can't see black in these but if you see tarry black (malena) in a puppy's faeces then it usually implies digested blood (ie bleeding higher up in the digestive tract and that the blood has then undergone the digestive process) so always ask your vet to triage in case of an emergency this in instance.   Sometimes, in an otherwise healthy dog, faeces appears mottled / mixed when an older, drier or different coloured poo, is mudged together with a more recent / wetter one in the large bowel.  This might, for example, happen if a pup has been holding their faeces / undergone a rapid dietary or hydration change.  However, if unusual faeces persist then this could reflect more ongoing physiological changes so again, always consult your vet.  Very black  tarry poos deserve urgent triage.

Great thanks for your reply.  It is invaluable.