Because the pet food industry uses waste products from the slaughterhouse industry, the "4-D" is just the start.
The ingredients in pet food often contain something called "meal". Beef meal, chicken meal, fish meal.
It isn't necessarily MADE from beef, chicken, or fish, it just SMELLS like beef, chicken, or fish. It is actually the waste from slaughterhouses, ground up into a slurry, and cooked in large vats.
Another not commonly known ingredient of "meal" is rendering plant waste. The rendering plant is where dead animals go. Including animals that have been put down at animal shelters. All those strays, those unwanted kittens and puppies, those old animals with diseases -- all part of "meal", which is a main ingredient in many pet foods.
Waste products from slaughterhouses include the spinal column (mad cow disease, remember that one?)and other internal organs that can't be sold as human food.
Another factor to look at with pet food, is the amount of grain used in it.
Dogs are basically omnivores who prefer to eat meat; cats are carnivores, so why are they being fed wheat and corn? Is anyone paying attention to the numbers of household pets that are getting Diabetes? Heart disease? Cancer? Why do you suppose that is?
I refuse to feed my pet anything that contains "meal" or has wheat or corn in it. After 3 years, the vet is amazed at how healthy my pet is! (normal weight, glossy coat, shining eyes, sound teeth)

Dogs are primarily driven by their sense of smell and their sense of taste is comparatively weak. Therefor, there is little to be gained by a taste test (I can't believe you did that!) because dogs probably don't taste their food as much as smell it.

This probably also explains why your dog is attracted to whiffy roadkill et al. It smells much more interesting than baked kibble (of any stripe).

Of course I'm not saying that feeding your dog recognizable ingredients isn't important or beneficial, I'm just trying to explain their "lack of taste."

I personally switched from being a long time(close to 20 years) IAMS customer to a new food.  Even though I feed predominately dry to both my dogs and cats.  I was a bit unnerved that some IAMS canned foods were in the melamine recall.  I switched to food from Healthy pet net.

I want to know what is up with all the promotion in commercials, the web and other places of High Fructose Corn Syrup??  I think they are full of it with their new adds that say HFCS is safe.  I have SEVERE allergic/sensitivity reactions to HFCS but not to regular corn syrup. I guess they think we are gullible and actually believe commercials.  Though sadly I guess some people are susceptible to them.

First, I am a vegan. One of my greyhounds thrives on a home cooked vegan diet (I'm not thrilled with all of the soy, corn and wheat in vegan options available at the store). The other does very well on the BARF diet (which actually stand for "bones and raw food" and is grain free). He also does well on other grain-free options as he doesn't tolerate too much quinoa, brown rice, millet or any other grain. Many dogs don't tolerate grains, but some do fine with them.

After a handful of years of trying various foods (none from the regular grocery store, by the way), I've come to the conclusion that I cannot advise anyone that any particular diet would be best for their individual dog.

Other than "feed actual food" as advice (rather than the crap most commercial pet food provides), my advice is to try raw if you can deal with it (there's also raw kibble--and soak any kibble before serving), try grain free, try high-end, wholesome foods like those from The Honest Kitchen, and pay attention to (and record) the reaction of your dog to what you're feeding her until you find the food that's best for her, then get her bloodwork done in 6 months and make sure she's getting everything she needs.

I'd love to say there's a one-food-fits-all answer, but in my experience, it's simply not that easy.

As a vegetarian, I have fed my Samoyed an organic vegetarian or vegan commercial dog food plus bananas and other fruit, shredded rice cheese, and occasional vegetarian table food, all of which she loves.  She appears to be extremely healthy after 4-1/2 years of such consumption.  I continue to feed my three cats Science Diet meat products in view of the fact that cats supposedly cannot thrive without animal products.  I've always been a bit suspicious of that claim, but continue to follow the latest "scientific" advice on the matter.

Marylou Noble
Portland, OR

Marylou Noble

So what, exactly, is high fructose corn syrup doing in dog and cat food?! Clearly, it is a nutritionally devoid yet caloric filler to make up for the caloric deficiencies of the other ingredients in pet food.