Hi Carol;
Like I said earlier, I'd ask my Vet.
He wasn't sure of the ingredients, but he explained that it must be the measurements of some ingredient which makes it unhealthy for dogs under 22lbs. Breaking the stix doesn't cut the ingredients in half. He said if it's on the package, then it means do not give to dogs under 22lbs.
Earlier today I replied with a link for these stixs,which has these stixs for smaller dogs.
Hope this answers your question.
