[rayray08]

Is he allergic to grain? Or do you just have him on grain-free as personal preference?

I'm considering getting some for my dog, although she weighs 6lbs.

Zuke's actual website states this as reasoning for not giving a dog under 5 lbs their bones.
"Your dog's safety is the most important thing to us. Because of how small the digestive system is in a five pound dog, the small Z-Ridge is more volume than we feel a dog of that size can safely eat."

I think this statement is based on the "feed one per day" method. I think if he's chewing it over a week it should be fine. I wouldn't feel safe giving him a whole one in a day. How old is Snick, btw? Puppies sometimes have a more sensitive tummy and too much can make them sick.