[Ellie May]

That could be a factor if any of them contain xylitol. But the fluoride thing is a major concern. Don't some even have the warnings that if more is swallowed than needed for brushing, seek medical help... Fluoride is said to bo more toxic than lead. So it can't be swallowed in large or concentrated amounts (there is a huge debate about why it is in toothpaste and the water supply at all). So anyway, a little Yorkie swallowing enough to brush with would be a huge problem.