Skin Issues, Allergies and Conditions

For dry flakey skin on my german shepard I used 2 tbl spoon of olive oil once a week on his dry dog food till gone. I mean when I got him it looked like bad dandruff on a black sweater. He also had a 1" & 1/4 long, about 1/2 tall tumor looking spot on his butt he was nalling at- and it cleared it up also. Also his coat became so shinny it looked like I had wipped him down with the olive oil.