Could anyone please advise on the best thing to use to get rid of or prevent tear stains on a white coat?  Thank you.

Never had the problem myself but I have read that raw feeding can help, no grains of any kind!
Easy to change over without tummy upsets, clean and no mess or blood, can be purchased from most good pet stores with a freezer.

Its basically down to genetic's,allegies and/ or the structure of the eye sockets that determine how tears drain away.

Both my mine have the tear stains, red dye and yeast caused by excess wet eyes for entirely different reasons......after endless researching and talking to a mentor I finally got a degree of control.

They are on home cooking which cuts out artificial dyes and additives that can stain the hair. Otherwise a quality grain free kibble and filtered water are important....... In some dogs just the filtered water helps a great deal.

A spray twice a day of 30% Collidial Silver directed into the eyes and face prevent excessive tears which lead to the staining, it also kills bacteria or yeast that's on the hair. After spraying both get a careful application of powdered borax onto the hair with a small makeup brush which acts as a wetness absorber keeping then stains from spreading and it also has a moderate bleaching affect which lighten the stains in time. As new hair growth comes in the old stained hair can be trimmed away. If you have a long haired dog, any hair around the eyes are kept short to allow air flow helps also.

Anything you do must be maintained viligently daily. I have Before and After treatment photo's if you are interested in seeing the difference. Also a article I found that explains why hair turns red if you want to read it..

This summer has been especially difficult with hot temperatures and high humidity ....any moisture of the hair quickly grows bacterial, yeast and finally red dye.

If the parents have tear staining then you might not beable to stop it. As Pipsmom says it can be down to genetics so if the tear ducts are too small then the tears cannot drain naturally so drain down the fur.

Apparently, apple cider vinegar in their drinking water helps x

Thank you all.  I think it's just a seasonal thing as it's only recent