blood in fecal matter

Question
it happens every once in a while our jack Russell will have loose feces and there will be blood in it.  Is it something he ate and he's stresses?

Answer
Stress can certainly cause this but it is usually from eating a surprise of some kind, a bite of human food, something he ate in the garden etc.

Dogs are geared to eat one thing only, all the time so any extras can cause some major gastric disturbances. Some of these can be very serious so don't feed him any people food at all, and keep him on a high quality diet that doesn't change its formula every new batch.

Unfortunately, the only food out there now that doesn't is Science Diet. I say unfortunately because most people feed cheaper store brands and even Iams now has lost their fixed formulation so pets that are used to once batch can get sick from the next one. SD doesn't switch out their ingredients and so that won't happen on their diets.

Watch his patterns and see what it might be but those are the most likely causes.