I am going to be using Sentinel tabs starting in June. The Brown tabs are for dogs 2-10 pounds and the green are for dogs 11-20 pounds. Vanilla is a little over a year old and last year she was 7 pounds and had the brown tabs. Well now she is 12 pounds exactly(Big girl, vet says should be 10-11 pounds for her frame) I noticed the green tabs are more than double the amount of medication. Do you think it is safer to stick to the brown tabs 2-10 pounds?