Try Kalkstein, if you sold any to him earlier, he should still have them.
There's no legit way, but you could try the save editor though.
http://witcher.gamepedia.com/Save_editor
http://witcher.gamepedia.com/Save_editor
You can get Beast fangs from these "monsters".
http://witcher.gamepedia.com/Beast_fangs
You can probably get one from the Mutant that is mistaken for the Striga. Otherwise I doubt you can find any dogs, and the armored hounds are found in Azar's Mansion, which would be too late for you.
http://witcher.gamepedia.com/Beast_fangs
You can probably get one from the Mutant that is mistaken for the Striga. Otherwise I doubt you can find any dogs, and the armored hounds are found in Azar's Mansion, which would be too late for you.