Been feeding mine raw wild salmon at least once a week, which I hope is enough. I may get some sardines too, and I have Natural Factors Wild Salmon oil capsules. The trouble is with fish oil is that they may need some Vitamin E to go with it. I used to add Vit E to the ground raw meat food I made, just before I switched them to unground raw meats.
All the other meats in their diet are high in Omega 6 fats, because corn and soy are so commonly used as feed these days. Even if it's organic grain fed, that means it's high in Omega 6 PUFAs, and it needs to balance with Omega 3s.