Health issues include but are not limited to:
temperament
rage
shyness
unstable
health
DCM
demodex
cancer
wobblers
liver failure
kidney failure
light sensitivity
bleeders (as in VWD)
thyroid
bloat/torsion
missing teeth
allergies (food & environment)
blindness
dysplastic (hips & elbows)
tearing ACL's

Be sure to do your research on the breeder you choose before purchasing a puppy. There are too many puppy mills out there selling dogs with these issues. Make sure these are nowhere in the bloodlines.