In the spring they are covered with white blooms. They do not produce edible pears and have a hard round berry instead that birds like, that's why they are invasive "poop !!"....ha.... and although I don't know from experience, I read they could be toxic to dogs. I never really see the berries on these, because the birds eat them up too fast.
Bloody hell, they look marvellous!
Stuff the dogs, it might mean less poo on the pavements :OD