Drank Dilute Betadine antiseptic
Hi, i recently was trying to save a bird that had been injured. I add 3-4 drops of Betadine antiseptic to a glass of water(about the volume of a soft drink can) to help his injured sores. The solution was very dilute, only with a slight colour of Betadine. I put the empty unwashed glass next to the sink while i walked away for a second to attend to something important. My brother filled the unwashed glass with water. I only noticed when he had drank the glass of water and he said that the glass of water tasted strange. What will happen, what should i do and what's the symptoms?

I'm really frighten what will happen to him, please help!