The "euthanasia" word has been twisted again to defend the indefensible. Killing a healthy animal is not euthanasia, but the word has been bastardized for so long by so-called humane societies that hold million-dollar contracts to dispose of society's unwanted pets that everyone else misuses it too: the media, animal rescue groups (to their shame), and lawyers. This lawyer is not the first one to defend the killing of healthy animals by calling it "euthanasia". PETA used the same false defence of its killing of puppies.
http://animaladvocates.com/cgi-bin/newsroom.pl/noframes/read/15349
PETA founder admits to killing dozens of animals a day