Where to begin? All commercially-available pet foods have one thing in common: their manufacturers want you to feed their food to your pet. Quality, like any product on the market, is highly variable. You can probably buy a 60-pound bag of questionable-quality dog food for $30, but I wouldn't go for the cheapest. Conversely, I don't subscribe to the notion that pet foods require "human-grade," "holistic," or "organic" ingredients. Pets are not humans - these are highly effective marketing ploys. Don't fall for them (THE SAME MARKETING IS USED ON US TO BUY OUR FOOD!) That said, many moderately-priced pet foods are indeed high-quality pet foods (because of their ingredients and not for what's written on the bag).
MYTH: By-products are unhealthy for pets.
TRUTH: There is nothing inherently wrong with the use of animal by-products in pet foods. Quite the contrary in fact. Many humans eat animal by-products: sweetbreads, tongue, liver, kidney,... pretty gross to many of us but not necessarily any less healthy (or less morally acceptable) than eating the muscle (steak, pork chop, chicken breast) of any slaughtered animal. That a pet food contains by products doesn't and shouldn't imply that it was made with ground up leather shoes and raccoons.
MYTH: Wheat and corn are bad for pets.
TRUTH: Wheat and especially corn are great sources of energy for both dogs and cats. Some dogs, especially those fit canine athletes out there, require huge amounts of energy for their level of activity. Cats are a totally different story. Because they are obligate carnivores, their level of carbs should be kept to a minimum, ideally less than 6 per cent. Kibble will have a higher percentage of carbs and many cats will have no problem eating these. Carbs are required to make gravy so I advise cat owners not to feed their cats canned foods containing gravy.
While cats and dogs can become allergic to wheat and corn, there is nothing inherently allergenic in wheat and corn. Not any more than chicken, beef, potato, or other protein and carbohydrate sources. Just because you have celiac disease (wheat/gluten allergy), doesn't mean your pet has it or will develop it.
MYTH: Food made with lamb is hypoallergenic.
FALSE: Before lamb became ubiquitous in pet foods, lamb was hypoallergenic. Not anymore. A dog or cat can become sensitized to virtually any ingredient in their diet and develop a food allergy. A true hypoallergenic diet contains ingredients that the pet has never swallowed in its lifetime. That could be pork, catfish, sweet potato, barley, oatmeal, ostrich, horse, kangaroo, and rutabaga (list not complete).
Diet should be tailored to the individual, just like in humans. A 4 yr-old, Jack Russell terrier, that is active, with an excellent body condition (not fat), with an iron constitution may thrive on a plethora of pet foods out there. A 10 yr-old, obese, severely arthritic, Labrador Retriever, with a sensitive stomach, would get something different: she'd benefit from a low-calorie, high-fiber, easily digestible, combination of high-quality kibble and/or canned food(quantity measured to the last calorie).
Have your vet help you choose the diet that is best suited for your pet. By the way, calorie-counting works!
Lots to write about so stay tuned for more on pet foods...