When Teddy still had puppy coat problems (tendency to tangle), I used Pet Silk silk serum on him. A little dab worked through his full coat helped prevent tangling.
Jenny, YT member Mimimomo sells it on her site
http://www.toplinepet.com
You can find the silk serum toward the bottom of the page here:
http://https://www.toplinepet.com/pet-silk.php
Jenny is awesome and has lots of great grooming products. Good conditions too that will help keep the tangles at bay.