Paedophilia -- nay, sexual child abuse (paedophilia being merely a particular paraphilia, although one almost always found in notorious sexual child abusers, excepting those that act on other motives than sexual lust) -- laws are inherently problematic.
If you -- quite sensibly, IMO -- dictate that a certain minimum level of maturity has to be reached by both partners involved (or neither) for the notion of a consensual action being valid, you need to bind that restriction to something legally tangible.
Age is the currently most widespread factor used for this binding, even though its relation to (physical AND mental) maturity seems to be rather arbitrary, although within a certain, limited, range.
Basing the capability for consent on physical maturity seems stillborn -- that much seems clear (the variations between physical maturity and what we would consider as appropriate overall maturity seem too whimsical).
I'd wager that psychological tests -- much like those used in courts to establish the maturity of a young criminal prior to deciding upon an appropriate punishment -- could provide a more sensitive alternative.
Then again, who'd want to have to seek psychological testimony prior to a virgin sexual act? The idea is pragmatically off-putting at best, not only because similar tests would have to be used to determine maturity when it comes to capabilities of contractual consent (i.e. whether one needs parental consent for certain contractual agreements with third parties).
I'd wager that a refinement of the text of the law based on a statistically averaged age limit and psychological tests (by several independent experts) for exceptional cases would be the best bet. A purely age-based system may result in the occasional false negative, but it's really the false positives you have to worry about -- and those are largely covered by separate restrictions (e.g. mental handicap-specific laws).
But I digress.
Pooch-rape is most definitely non-consensual, except for a few rare cases where the pooch suffers from an odd taste. Rape-by-pooch, on the other hand, would be difficult to prove -- you could make a point for sexual harassment, but rape by a creature physically inferior and not even possessing opposable thumbs? You could more probably sue its owner for improper guidance than blame the pooch.
Inter-species sex is a difficult issue anyway. There is no particular reason we should treat humans as special. Other animals are generally considered as incapable of consent -- but can we really treat them legally as children if the reason children are treated specially is that they will eventually develop adult capabilities?
In fact, a mature chimp could hardly be considered a child in legislature for exactly the reason that he is fully developed already, whereas the child is in a fragile larval stadium, not yet fully developed, both physically and mentally.
I guess we could make a better point for treating other animals as particular cases of mentally handicapped humans -- the less capable of human-like thought they seem to be (not necessarily the best criterion, but better than the traditional speciecist perspective), the more "handicapped" -- though, if this train of thought were followed, particularly handicapped humans would only, consensually, be able to mate with the similarly handicapped and certain other species of apes -- no need to be a red-blooded speciecist to see the problem with this.
What if we had a smooth gradient of surviving intermediate forms, back to the great aunt of chimps and humans, still alive and kicking? How distant would the relative have to be so we could have sex with them? Would potential for genetic compatibility factor in? Certainly we'd have to keep up a lower threshold for genetic distance or incest would become necessarily legal.
Sex is easy. Justifying it can be difficult. Finding logical reasons to outlaw it can be near impossible. Put protecting the innocent never has been the easy thing to do, anyway.
Sorry for the rambling. Back to the original topic:
That child IS a hardcore gamer.