Louis, my 10 yr old, has been fighting staph/yeast on his paws for at least a month. I've tried Cephalexin, Ampicillin, Orbax, Ketaconazole, & Benadryl. His paws are still red and he's still itching and licking. Have been trying organic apple cider vinegar, but that just makes him lick more. His food hasn't changed- he's on Blue Freedom Chicken and all of his treats are wheat/sugar free. So, I bought some colloidal silver today -500 PPM. The lady at health food store told me to give him 1/2 of a dropper 2-3 times a day- he's 35 lbs. She also said that I could put it on his feet. Anyone had experience with this and does dosage sound correct?