[QUOTE=SoCalyorkiLvr]I don't understand the concern because the statisitics (what few there are) do not show more health risks or genetic defects in smaller yorkies than in the larger ones. I do not think there is any scientific or medical reason that makes intentionally breeding smaller yorkies a bad thing. QUOTE]
Special circumstances often come with extra tiny dogs. They are extremely
susceptible to both hereditary and non-hereditary health problems, including
birth defects that may go undetected for a long time. Other common
problems may include, but are not limited to, diarrhea, vomiting, along with
extra and expensive tests prior to routine teeth cleanings and surgeries.
Small ones are more likely to have poor reactions to anesthesia and die from
it. Tiny dogs are more easily injured by falls, being stepped on and being
attacked by other dogs. These health problems nearly always result in
large veterinary bills.
http://www.ytca.org/faq.html