My two are on Omega oil now...but I used to use a dropper bottle and put ONE drop of Canola oil on their food (mix it into the wet). Guess I could have used more.

Their Omega oil is in a pump form...it's for dogs, but with the two of them being larger cats, one pump for them (one dog) is perfect. I smush it up in their wet food, then split the food in half.

I've also heard that tuna is not really great for pets...something about the mercury? Maybe someone else can comment on that.