I have a yorkie with no tear duct in her left eye so it used to get ulsers all the time before she had surgery but hers were only small and never progressed
the vet should give you antibiotics for it in the morning but for tonight you might want to ...
'designer mutt' what a brilliant term!
if people want to spend their money on a mutt, let them. as long as the breeders are responsible and the puppies go to good homes that is all that matters right