Dogs need essential fatty acids, omega 3 and 6 to maintain healthy body functions, and a good balance of the two reduces inflammation. The body doesn’t produce them so it has to come from what they eat.
Due to modern farming methods, foods are generally abundant in omega 6 but lacking in omega 3. Our optimal amount of Omega 3 and omega 6 intakes should be in the ratio of around 1:4 (no more than 1:10). Yet, some foods offer as much as 1:20+ ratio of omega 3 to 6.