[C4D]

I use human fish oil for my dog that has arthritis in both hind knees due to old CCL tears. It’s really helped for over 5 years. She has very minimal arthritis and walks well.
Here’s a link to VA which is very mainstream. They seem to prefer fish oil.
http://www.vcahospitals.com/main/pet-health-information/article/animal-health/flax-seed-oil/458