Why would atoms decay to photons? If they would manage to stay out of black holes, they can't totally decay to photons. Say an atom contains equal amounts of electrons, protons, and neutrons. Now, a neutron, proton, and electron dont contain equal amounts of preons and anti preons, so they can't annihilate each other completely. Say we have one electron, one proton, and one neutron. An electron contains ttt a proton, TTVTTVtvv and a neutron TTVtvvtvv (where T,V are the charge 1/3, 0 preons and t,v are the
anti preons). You see that we are left with vvv, an anti neutrino. Maybe if this hits a neutrino,VVV, it can produce two photons. Anyhow, the information will be in the photons, like all photons and neutrinos evaporated from black holes, in zillions of years will contain the information of all matter once in existence. To say its retrievable is a fairytale though. It will be scrambled-up pretty badly (not to mention $%^&%$-up...). Somewhere though, the memory of your lovely dog will be still flowing then... Small solace...