Well, in Kodi's case, neither beef (grass-fed or otherwise) not ANY kind of fish or fish oil) are a possibility.In my raw feeding groups, I have seen a change in attitude towards fish oil over the years. It used to be highly recommended for anyone who could not feed their dogs pasture raised meats. In particular, grass finished meats such as beef have a great omega 3 to 6 ratio. Animals that are not raised on pasture are way too high in omega 6, especially animals who are fed lots of corn and soy. Vegetables also are high in omega 6 and omega 3s in vegetables are not assimilated like those from animals. Therefore, most commercial dog foods are very high in omega 6. Homemade diets can be too because grass fed meats are super expensive and not everyone can afford them.
Adding fish oil is one way to improve the omega 3 to 6 ratio. However, the concern about fish oil is that it goes rancid very quickly when exposed to the air. Therefore, many folks have ditched the fish oil and are feeding fish instead like sardines and mackerel, or trying to add some grass finished meats to the diet. Here is one article about this.