[Ellie May]

Processed pet food that is complete and balanced doesn't need to be supplemented. It is really up to you. I only add supps if it is medically indicated. IMO, it is a big industry taking a lot of money from people unfairly and unnecessarily.

Fish oil is popular. Most pups (that aren't fat intolerant) do fine with it. But there is no established minimum dose. There is a certain amount thought to alter tissue levels, but it is not an exact science.

I'd base the decision to use a senior food on how your pups are doing and their labs. A normal senior does not need low protein, but potentially lower phosphorus. There are bo definitions for senior food. Each company decides what it should look like. But there is a lot of back engineering going on with smalker companies.