An update on the Leba, been using it twice a day for abut a month and it actually works! It doesn't quite clean up those top molars at the very back up under the cheeks, but all the rest are clean and free of plaque which I used to chip off every 6 months, along with vet cleanings about every 1-1/2 years.
This is really amazing, I'm now cutting back to one application a day for them. It isn't that expensive as it seems as it only requires a small amount sprayed into their mouth each day, about 1/2 hour before or after they eat or drink.
