Just wondering if anyone can tell me which if any health tests ought to be carried out before breeding from Papillons. I am aware they sometimes suffer from patella luxation or PRA but do not know if such things can be screened for? (I think there might be info about this on the KC website but I can't seem to access it) Thanks.

It  is only eye testing (no DNA test available so has to be done by an eye specialist) and patellas and patellas can of course be checked by any vet.