My lovely little boy Shih Tzu has really bad tear staining and it's starting to smell! I try and keep his eyes clean but it's not making any difference. He is fed on Barking Heads kibble which should be colour and additive free so I don't think it's that, but when he was fed on skinners he didnt have this problem?? Also his beard is a bit stained reddish brown similar to the tear staining. I know you can buy stuff for the eyes but the reviews on them don't seem to good. So I am open to suggestions please.