We have a 4 month old puppy who had green discharge coming out of his nose which cleared up but he continues to have terrible breath through his mouth and nose. Could it be sinus infection, the smell is not from eating anything he shouldn't.
Was this pup on antibiotics? Did he see a vet for the nasal discharge?
I would worry about potential for some sort of foreign body (stick, sliver,awn, other plant material, etc) in the nasal cavity, soft palate or related tissues.
Puppies can have some odor (bloody) when they are losing their deciduous (baby) teeth and the adult teeth are erupting, but should NOT have a green nasal discharge. Another potential cause would be an abscess tooth (especially a canine) root.
Highly recommend having your vet check your pup out.
Green Nasal discharge is a symptom of both Kennel Cough/URI and Distemper also! It may have been a case of URI that cleared up on its own... sometimes it does. That shouldn't affect the breath though. I've seen dogs who were treated for distemper with enamel damage from the antibiotics, have teeth problems later in life. I would have your puppy seen by a vet right away. As previously mentioned, he could have a foxtail or other debris up his snoot.