Metallic Puppy Breath

Question
My 4 month old puppy has a metallic odor to his breath.  He has been vaccinated and to the vet for an injury to his eye but I kept forgetting to ask why.  His appetite and bowels are normal, very energetic and very healthy.  I have switched puppy foods thinking that was the cause but it's still the same.  Is this something I should be concerned about?

Answer
At four months of age puppies are starting to lose their molars and they can bleed a little when that happens. I have smelled this in puppies this age and upon examination their gums are a little sore. Blood smells metallic so I am going to guess and say that is why you are smelling it.
Since he has one more vaccination to go write this question down now and put it in his baby records and take it with you and ask the vet about it. By six months most of the teeth are in and the canines are coming in. So the smell usually is gone by then.

Go write it down before you forget!