Stool concerns

Hi I'm looking for some advice on my 10 year old dogs stool this morning.   This is the first time in his 10 years have I ever had a concern, he went and passed some blood. Photo attached

Thank you for the photo.  Blood is never what you want to see in a stool, but it can turn up for a huge arrange of reasons, from quite benign to very nafarious.  These include worms, scratchy objects e.g. plant-matter in the faeces, failure to clot (eg liver disease, cancer, blood disease, toxicity), an ulcer, polyp, benign lump or tumour.  Your vet can carry out a sequence of tests in order to try to work out what is responsible for this;  it is worth getting their co-operation early.

I would not expect your vet to solve this one in a single consiltation; blood tests, parasite tests and an endoscope may be offered.  If worms is a reasonable possibility, some vets may aim to rule these out first by testing or treatment.