Yorkshire Terriers

Hypoglycemia as puppies—high energy
Supplements often used first 6 months of life
Porto-systemic liver shunts—early detection blood screening is critical
Medial luxating patellas, "slip knees"—keeping body condition lean can help knees cope with dysfunction
Periodontal disease - good oral hygiene is a must in this breed or they will have oral disease early in life.
Some Yorkshire Terriers can be "yappy," barking at every sound they hear. Early and consistent training can help.