I think i was thinking along the same boat as you i read somewhere that a salmon head was good for the mutts had Omega 3 etc and loads of other goodies , but now i just get enough scraps and fish heads to feed the ferrets once a week as a change from meat , Its nice to see some of the strange coloured fish heads etc but i reckon the dogs will get the same goodies from a tablet ?
Then the next question is where do you draw the line ?. Multivitamin tablet , cod liver oil tablet , omega 3 tablet , Garlic tablet ?.