How much does Bonzo weigh now at 6 months old?  How often are you feeding him and how much are you feeding him at each meal?   
By the time my yorkie was 6 months old she was eating maybe twice a day.  I got her home at 13 weeks and maybe a week or two later she stopped wanting lunch so instead of 3 meals, she was getting 2.  Then she stopped eating all her breakfast, but all of her dinner.   Eventually, since she isn't a speed eater, i just started leaving her daily amount of food down all day and she was free to eat whenever she wanted.  She's 4 years old now, a little less then 5lbs, and still eats whenever she wants.  Some days she doesn't eat at all.  i don't worry about it though.  If she's hungry, she knows where the food is and can help herself.  She's even gone 2 days without eating and has been fine.  I've never had to hand feed her, and she's never had a hypoglycemic attack.  very happy and healthy.     
				__________________  Kellie    and    Morgan      |