Have you ever read the article "What's really in dog food?"
Well, I've read something close to it. And yes, I agree, commercial pet foods are garbage with the exception of a few human-grade foods. Iams used to be good (like 15 years ago - whatever they have now makes the dog want to poop 10 times a day).
My lab gets a lot of "supplemented" human food when he cruises the counters or eats at the old Trash Can Buffet :)
The cat, having been diagnosed with Leuk & FIV, is on Wysong or Innova (depends on if the dog eats it all and I can't make it to a mom & pops pet store to get the Innova.) Vet recommended interferon therapy - cat shriveled and lost a lot of hair, lymph nodes enlarged to the point he couldn't swallow.
I said enough of this: changed diet, changed litter to a pine/paper pellet mixture, I throw a couple drops of silver on his fur every other day for him to lick off and add an antioxidant supplement daily. Cat gained 4 pounds, fur is back, eyes clear and lymph nodes are only a tiny bit enlarged. Respiratory infection (treated with 2 courses of antibiotics to no avail) is gone. Cat attacks Lab again, so I KNOW he's feeling good ;)
But you know, all this stuff simply "supports" health and doesn't cure anything (big wink).