Just a note here.
Fish Oil vs. Flaxseed Oil
Flaxseed oil contains more Omega-3's than fish oil. However, the Omega-3's in flaxseed oil are in an inactive form (ALA). Special enzymes are required to convert the inactive ALA into the active forms (EPA and DHA). Some animals, especially carnivores like dogs, do not have the required enzymes to do the conversion.
Recent research shows that fish oil has more positive benefits on pets with disease, because the fatty acids contained in fish oil are readily available for use already in the converted form EPA and DHA. Particularly, fish oil has positive effects on dogs with inflammatory diseases, such as allergies, arthritis, kidney and heart disease, and cancer. Flaxseed oil does not seem to be as beneficial to dogs with inflammatory diseases.
However, flaxseed oil seems to be anti-cancerous, and is also effective in improving the skin and coat conditions of dogs.
Flaxseed oil can be a dietary source of soluble fiber. Increasing soluble fiber in the diet can help counter tendencies to constipation.
Fish oil, therefore, is the preferred fatty acid supplement for dogs with inflammatory diseases. Flaxseed oil can be used to improve skin and coat conditions, and to counter constipation and perhaps inhibit cancer growth.
Also flaxseed turns rancid quite quickly after it's ground up so it's best if you can grind only the amount needed and store the seeds in a glass jar in the frig.