Am I right in thinking that he will only eat what is good for him, or should I stop him doing this?
While most animals are capable of self-medicating to a high degree, there remain some which will eat substances that are bad for them, so the educated eye of the owner is essential.
I have known dogs to make themselves very ill by eating ragwort, bracken, toadstools and other toxic plant life, or by swallowing wood or stones and causing a blockage.
Rotting bird carcases are often eagerly devoured, but are havens for unpleasant bacteria and can cause severe digestive upsets.
It is useful to be able to identify common poisonous plants, and to teach a ?leave? command, and also to know which weeds and grasses are safe and beneficial to your dog.
However, a dog which is continually scavenging may have a health issue, most of which are easily treated once identified, and I would recommend visiting a good holistic vet who will look past the immediate behaviour to find the underlying causes.