Essential fatty acids from fish, including EPA and DHA, have many potential benefits based on sound theoretical and in vitro work showing their potential to reduce inflammation. There have been very few studies in companion animals on their usefulness for arthritis, and these do not seem to show much if any benefit, though the work is preliminary. The research in humans is also variable in quality and in results. Fish oils are very likely safe for most pets, and they may or may not have any beneficial effects on arthritis, but the data so far is not encouraging.

I agree that there is a plausible theoretical mechanism for a posisble benefit, I simply don’t believe these studies demonstrated an actual meaningful clinical benefit. I even agreed with the study authors that further research is warranted. But it is important for people to understand that most extrapolations from fundamental principles turn out not to work in clinical practice, so just because something might work isn’t proof that it does. Hopefully, further research will find real benefits, because I would love to have yet another tool for dealing with arthritis. But so far, the data are not encouraging.

BTW, the page numbers on the second citation should be 67-73.