Having tuned back into Gw2 again after a long absence, I noticed the February 22nd patch notes describing how many pets got functionality tweaks to make them better target trackers.
Having tested several of the pets out since this change, I noticed something of an anomaly with the way drake pets use their tail swipe – it appears to be that they only use the tail swipe ability at the edge of its effective cast range (which was recently increased.)
It is effectively never used when in prior months it would reliably be cast against targets.
Uncertain regarding Chomp – it appears to lack an animation cue (or it’s being mistaken), but evidence leans towards it not functioning properly either, if measured strictly against “Does this pet ever get a health return of its own making?”