i have 3 different fish charts. one is for mercury/etc and is a basic quickie for shopping, another is the Monterey Bay Aquarium's, which really breaks it down by fish/sub fish and a third which breaks it down to often you can eat it. I feed my cats/dog salmon from alaska, wild caught river. either canned or fresh poached. just do it in moderation

i can get what's called soup fish, which is basically salmon trim from making salmon steaks. i poach that in a bit of homemade chicken broth. the canned i used is crown prince wild caught from alaska. nothing added. you can buy it by the case on amazon. i also bought another brand recently, same specs of amazon

my pets also get my leftover salmon.
you can also get grizzly salmon oil to add to their food. wild caught alaskan. my cats and dog go for it just fine whether off my finger or a squirt on their food.