Grisioflavin prescription for ringworm

Question
Hi - My 11 year old dog has gotten ringworm - he is on grisioflaving (sp?), but when I go to my vet for refill of his prescription - the first time they said to give him half a pill once a day and then the next time I had it refilled - they said give him a half a pill twice per day.  There are 3 vets in this office and I've gotten a different prescription from each one, so I don't know which one is right.  The dog is 28-30 lbs - has had ringworm for 2+ months and has about 60 lesions on him.  He appears to be improving slowly, but I'm concerned that I am under or over medicating.  Please help.

Answer
There are different strengths of the Griseofulvin microsize tablets, so they may have given you two different sizes. There are also 2 dosing regimens.  One is 25 mg/kg twice a day and the other is 50mg/kg once a day. You should call the vet clinic and find out if there was a mistake, or just 2 different ways of medication your dog.