Symptoms of Hypoglycemia in Dogs
Here is a link to an article on this.
I would be feeding this wee one 4 times per day at least 1-2 TBLSP per meal, and also give him a TBLSP prior bedtime.
Also if I notice an establish - immediately use the honey or the maple syrup, or in the States you have something called Karo syrup and then try to get him to nibble on some food.
And then call your Vet.