Poultry and vegetable oils are very high in omega 6’s. For most dogs, omega 6’s aren’t an issue. In fact most dogs (and people for that matter) get WAY too many omega 6’s. Ideally, a diet should have roughly a 5:1 ratio of omega 6’s to omega 3’s (some sources recommend a slightly lower ratio, others say a slightly higher ratio is okay) – the diet of a typical America (and most dogs too) is usually closer to 14:1 to 25:1. So it’s necessary to supplement with omega 3’s in order to get closer to that 5:1 ratio.
These articles have some good info:
http://articles.mercola.com/sites/articles/archive/2012/01/12/aha-position-on-omega-6-fats.aspx
How Too Much Omega-6 and Not Enough Omega-3 Is Making Us Sick
