None of us know for certain what Eddie was trained to alert too, Sadie. Only the trainer would know that. However we do know that he could alert to blood from a living person (which had dried) and IIRC, he alerted to semen on a tissue in another case.
X contamination could be another cause for alerts. False alert is also a possibility.
Living scent as in a human scent, would be everywhere in the apartment.
SAR dogs who do this kind of search (live victims) usually do so in searching outside areas or areas of disasters, they will also find a cadaver if one is present.
Please feel free to correct me on any of the above, which is only my opinion.
Grime's wording isn't always clear.
According to Grime's rogatory statement, he wasn't trained to find "live" odours and I don't recall ever seeing anything to suggest that Eddie was ever trained as a search and rescue dog (let alone as a tracking / trailing / SAM dog).
Even what he means by "live odour" isn't entirely clear. Does he mean "live odour" as in a SAM dog? This seems unlikely (IMO) if he wasn't trained to track an individual person.
However, from his profile statement, does state that he would "search for and locate
human remains and
body fluids including blood.That has been interpreted by some to mean body fluids from a corpse, and it isn't until his rogatory statement that he clarifies that he would react to dried blood from a living person.
It's not clear what other "body fluids" he may react to that were deposited by a living person. There's some ambiguity over whether he was reacting to semen / vaginal fluids on the Jersey clean-up tissues, blood, or both.
I believe that someone else (Brietta?) also posted this from an interview with Grime in the Sun in 2008:
‘Eddie smells for the scent of a decomposing human body. He can detect any part of a human body that is decomposing ‘ hair, bones, flesh, anything.
‘The smell of a decomposing body is very difficult to get rid of. It can easily be transferred to clothing and on to a person.’https://madeleinemccannthetruth.wordpress.com/2013/08/10/misinformation-those-dogs/
The key seems to be whether the substances are in a state of decomposition or not, thus giving off the various characteristic smells, and are deemed potentialy relevant to a particular investigation.
I haven't come across anything that states that he was trained to ignore even urine / fecal matter. Personally, I would have thought that NOT training him to ignore such subtances would be more of a hindrance than an asset, but then it might be useful in certain (limited) scenarios.
From what I've read, hair and nail clippings don't actually decompose for some time in normal aerobic conditions (whether that is accurate or not, I don't know).
In humid anaerobic conditions, skin cells decompose to give off a characteristic pong (I'll post a link if and when I find one again).