When we give it we put a small amount of anything for a treat in a bowl - usually a pinch of shredded cheese, add the DE to it then mix some water in to make it creamy - since it has no flavor they don't notice and its easy to trick them -by using a small amount of treat for this I know they eat it all and with it being creamy I feel like it gets in their teeth to help clean them too ( their breath is better since doing this also )
Our dogs are approx. 60 and 80 lbs. and get a heaping tablespoon daily - I keep an eye on their poo to make sure it doesn't get to hard - so far they do fine with that amount - your dog will get large, but I would guess if you do this daily now as it is "smaller" it should all ready be in its system and could be maintained with a tablespoon when it is huge - for adult humans it doesn't give weight/dosage , I don't weigh as much as my hubby but we take the same amount ( 3 tablespoons) - you will know if it is to much because it will cause constipation