That is incorrect.Untrue. Eddie alerts on old/dried blood from live humans too.
Source: Madeleine Files, Martin Grime interview
If that was the case he would never have passed the Police trials and acquired his license to be used in convictions.
He doesn't respond to blood. What is the point in having Eddie and Keela in a team when both of them respond to blood? You might as well just have Keela the blood dog.
Eddie responds to enzymes and chemicals which make the 'death smell'. That death smell is released postmortem and the minimum is two hours after a body has expired for it to be released. Blood can be released from a human at anytime.
Cadaver dogs smell dead bodies and the chemicals associated with them not someone's casual nosebleed.
There is not a authority in this land that would give a dog a license to be used in prosecutions that could be confused by a nose bleed.