So "tea cup" dogs don't exist? or do they?

Runts that are below the breed standard sizes do exist. However, they are a not a separate or recognized size/cl/breed. They are just undersized individuals. They are inherently less healthy than their normally sized brethren and are prone to a number of organ and skeletal issues. They have much shorter life expectancies than normal dogs. The term "teacup" is nothing but a marketing scheme used by crappy breeders to make their runts seem more "special", when in fact you are getting nothing but a sickly, undersized creature.