Tinker had a very tough start.  When we got her from her breeder, she was malnourished to the point that she only weighed 14 oz at 8 weeks, when you would expect a puppy to weigh 3 pounds.  Due to the lack of adequate nutrition, her joints did not form properly, and when we got her, she was walking on the backs of her ankles on her front legs.  After a lot of TLC she turned out to be ok, but she will likely have joint problems her entire life from her rough start.  She is spayed and is our very spoiled pet.  Today she weighs a whole 7 lbs.