I HAVE A JACK RUSSEL TERRIER. WE LOVE TO TAKE WALKS, PREFERABLY OFF LEAD. UNFORTUNATELY, HE EATS ANYTHING AND EVERYTHING INCLUDING TRASH,OTHER PEOPLE'S BAGS OF DOG POO, IT DOESN'T SEEM TO MATTER. WHEN I TRY TO TAKE IT AWAY FROM HIM HE GETS VERY AGGRESIVE AND SOMETIMES YOU CAN'T GET IT AWAY FROM HIM (USUALLY THE POOP) ANY SUGGESTIONS? HOW HARMFUL IS IT?
It could be harmfull if he eats bad food, toxic garbage, Parasite infested poo, etc. I quess he does not do well of the lead so keep him on a leash. You will have more control over him. Also try placing a treat in his mouth several times during the walk. Vetcare