Try contacting Angela Perri at the Max Plank institute. A quick google for her should bring her contact details up. She did her PhD thesis at the same time as me in Durham. It was on dog hunting, burial and domestication and is bound to be able to help in some way.
Maud Pionnier-Capitan, Céline Bemilli, Pierre Bodu, Guy Célérier, Jean-Georges Ferrié, Philippe Fosse, Michel Garcià, Jean-Denis Vigne, New evidence for Upper Palaeolithic small domestic dogs in South-Western Europe. Journal of Archaeological Science 38 (9), 2011, 2123-2140.
As it seems there is no European database as such yet. But maybe we could help to bring together all jigsaw pieces in parts. For the Iberian Peninsula I would suggest to get in touch with Prof. Arturo Morales Muñiz. He is the leader of an ambitious project collecting all kind of information about this subject.
As far as I know they have got dogs from Neolithic to Bronze Age in archaeological contexts.
Gerald Munt & Christopher Meiklejohn, The symbiotic dog. Why is the earliest domesticated animal also important symbolically? In: Birgitta Hårdh, Kristina Jennbert, Deborah Olausson (eds.), On the road. Studies in honour of Lars Larsson. Acta Archaeologica Lundensia in 4o, No.26 (Lund 2007), 165-169.
here is an new paper (published December 22, 2014):
Marie-Pierre Horard-Herbin, Anne Tresset & Jean-Denis Vigne, Domestication and uses of the dog in western Europe from the Paleolithic to the Iron Age. Animal
For what is probably the largest collection of such remains in Europe (if not the world), contact the Albert Heim Foundation at the Museum of Natural History in Bern, Switzerland. Marc Nussbaumer would be the person to talk to.