He is a singleton...and is getting all that milk. I wouldn't worry at all...and he will lose that weight once mom starts weaning him...My Bailey was a singleton girl...my breeder and I call her a porky yorkie...LOL..she was off the charts as well....she lived 15 yrs and was only 5 lbs.
And he will learn all he needs to know from Mom but he must stay with her for 12 weeks or more
