These common pet food ingredients are despised by many. Yet they’re accepted… and even revered by others.

Fans claim animal by-products are equal in quality to fresh meat. And they blame the ingredients’ noted unpopularity on the unsavory mental image they invoke.

Something proponents like to refer to as “the yuck factor”.¹

Critics, on the other hand, insist these ingredients are nothing more than inedible waste of inferior nutritional value.

What Exactly Are Animal By-Products?

Basically, animal by-products are what’s left of a slaughtered animal after the edible parts have been removed. They include the waste² of meat processing not intended for human consumption. For example…

• Feet
• Backs
• Livers
• Lungs
• Heads
• Brains
• Spleen
• Frames
• Kidneys
• Stomachs
• Intestines
• Undeveloped eggs

But there are exceptions…

Giblets (livers, hearts, gizzards and necks) as well as other organs can be sold as edible meats or used generically to make hot dogs, bologna and sausage.

Unfit for Human Consumption
OK for Dog Food?

However, what makes some by-products edible (and others not) isn’t just a matter of what they are… but how they’re handled after slaughter.

For example, giblets not refrigerated immediately after slaughter but stored for up to 24 hours in a hot offal³ trailer cannot be sold for human consumption.

Yet they can still be legally used for making pet food.

Likewise, dead-on-arrival animals or other condemned parts⁴ that have been declared inedible and unfit for human consumption can still be used for making pet food.

Turning Tons of Inedible Waste
into Profitable Products

As you can see from the diagram, there are two primary uses for meat by-products…

• Canned pet food
• By-product meals

Inedible by-products not processed into canned pet food can be rendered.

Rendering is a process similar to making stew. Except that the stew is intentionally over-cooked.

With rendering, the idea is to start with a stew of by-products and cook away the water.

Then, skim away the fat and bake the residue.

What you end up with is a concentrated protein powder commonly known as by-product meal.

The Two Grades of By-Product Meal
(and the Only One Suitable for Your Dog)

In the specific cases of chicken or poultry by-product meals, there are two recognized grades…

• Feed grade by-product meal
• Pet food grade by-product meal

In an important 2003 study⁵, pet food grade by-product meal was compared to feed grade by-product meal.

The result? Pet food grade by-product meal was found to be…

• Higher in protein⁶
• Lower in ash
• More digestible⁷
• More consistent⁸

Bottom line? All things considered, pet food grade by-product meals are superior to feed grade by-product meals.

The Two Ways to Describe Animal By-Product Meals

Based upon the source of their raw materials, there are two ways to identify by-product meals.

• Named by-product meals
• Generic by-product meals

Named by-product meals have one thing in common. They all clearly identify the source species of the by-products that was used to make the meal.

These common pet food ingredients can include…

• Chicken by-product meal
• Turkey by-product meal
• Poultry by-product meal
• Beef by-product meal

And although named by-product meals may not be considered the highest quality ingredients, they can be considered acceptable.

And the One Type You Must Never Trust

On the other hand, generic by-product meals do not identify the source of the meat. Instead, they use vague and non-specific names like…

• Meat meal
• Meat and bone meal
• Meat by-product meal
• Animal by-product meal

What’s more, generic meat meals can also contain…

• Road kill
• Dead zoo animals
• Dead on arrival poultry
• Diseased and dying livestock
• Euthanized pets from animal shelters

Because you can never know the source of the meat used to make generic by-product meals, purchase of pet food products containing them should be avoided.

Nutritional Differences… Real or Imagined?

When comparing animal by-product meals with their “regular” meal counterparts, the differences can be nutritionally insignificant.

For example, in the case of rendered ingredients, the digestibility, biological value and amino acid content of both poultry and poultry by-product meals are nearly identical.⁹

So, if there’s little nutritional difference between the two, why then do some companies use meat by-products… while others don’t?

The Real Reason Dog Food Companies
Use Animal By-Products

There’s one glaring and indisputable reason animal by-products remain so popular with some manufacturers… and not others.

Animal by-products are simply cheaper… notably cheaper than most any other comparable meat product. They’re used for making dog food because they save money. Not because they’re more nutritious.

Why is this important to a pet food shopper?

Although finding animal by-products in a recipe doesn’t guarantee you’ve discovered a good or a bad dog food, their presence must always be considered a reliable clue the food is made with cheaper ingredients.

The Bottom Line

With the sole exception of precisely identified organ meats, two rules will help you more intelligently navigate the confusing world of meat-based dog food ingredients.

First, watch what you spend. Never pay top dollar for any dog food that lists animal by-products on its label.

And lastly, never buy any dog food containing anonymous animal by-products sourced from materials a manufacturer refuses to clearly identify.

Notes and References

For more help, watch Dr. Becker’s video and learn How to Choose a Good Dog Food.

To see Part 1, please click Dr. Karen Becker Shows How to Choose a Good Dog Food.

For more help, watch Dr. Becker’s video to discover The Best and Worst Types of Food to Feed Your Dog.

To see Part 2, please click Dr. Karen Becker Shows How to Choose a Good Dog Food.

For more help, watch Dr. Becker’s video to discover The Best and Worst Types of Food to Feed Your Dog.

And that can be a real problem.

Why It’s Difficult to Control the Quality
of Dog Food Ingredients

Not only do most pet food companies conceal the origin of their ingredients, they also change the sources as well as the quality of those ingredients on a regular basis.

Many raw materials used to make dog foods are bought and sold in commercial-sized lots on the open market.

Bulk prices vary. And so does quality.

From day to day, it’s not unusual for an ingredient to come from a different farm, a different storage facility or a different state.

Even a different country.

Although better companies procure their ingredients directly from trusted manufacturers, others may buy their raw materials through brokers and middlemen.

And many times through less-reputable third party suppliers.

What’s worse, manufacturers are not legally required to report these changes to consumers.

That’s why the method used to review a product is so important.

The Only Objective Way to Review Dog Food

Although there are many ways to rate a dog food, we’ve settled on using the only reliable information we feel we can consistently trust.

We read and interpret government-regulated pet food labels. Nothing more. And we do this in two simple steps.

1. We study the ingredients list
2. We estimate the meat content

As reviewers, we don’t test dog food. We don’t taste it. And we rarely trust marketing hype. Manufacturer’s claims. Or the fancy artwork on the package.

Nor should you.

Yet Those Nagging Questions Persist

Of course, like everyone else, we still yearn to know more…

• Where do the ingredients come from?
• Are they food grade? Feed grade? Or agricultural rejects?
• Are they fresh?
• Will my dog like the taste?
• Is the kibble the right size for my pet?
• Have they been tested for chemical or biological contamination?

These are all legitimate questions. Some of them can be answered by simply visiting a company’s website. Or calling their customer service number.

Yet remember, company information can be biased.. and almost always subject to change.

That’s why we’re reluctant to simply re-broadcast a manufacturer’s marketing message. We fear it could be misleading and provide a false sense of security to our readers.

Real Life Experiences and Results

Reviews can never predict results. However, there’s one valuable source of information that can help. It’s easy to access. Practical. And yet commonly overlooked.

Our readers comments.

So, be sure to check out the Comments section at the end of each review for a more complete picture of each dog food.

Before you buy.

There you’ll find a wealth of helpful information from our readers… dog owners and breeders as well as community-minded veterinary professionals, nutritionists and dog food companies.

• Tips and suggestions on feeding
• Candid opinions about specific dog foods
• Reports of real life experiences and results
• Comments about a company’s customer service

Best of all, find out whether our readers’ dogs give a “tails up” or a “tails down” to the taste of a particular product.

So, What Do Our Stars Really Mean?

We tend to dislike dog foods made with by-products of any kind (plant or animal). And we downgrade recipes that use controversial chemicals or non-meat protein boosters.

Yet we shamelessly favor dog foods rich in meat.

In general, a five star dog food is one that is high in meat content and free of any by-products, suspicious chemicals or plant-based protein boosters.

So, does that mean a one-star dog food is bad for your dog?

No, probably not. A product with a low star rating isn’t necessarily a bad product. Some dogs can thrive on these recipes.

It’s just that we passionately believe you should know what you’re paying for. And dog foods made with by-products and less meat should be judged for what they really are…

Lower quality dog foods.

The Bottom Line

The reviews published on this website are not intended to suggest that feeding a particular product will result in specific health benefits for your pet. They should only be used as a tool to help you make a more informed decision when buying dog food.

And remember…

Consumers are forever at the mercy of dog food manufacturers. Even with their well-meaning promises and guarantees, each batch of ingredients can be notably different from the previous one.

The variations in quality of the finished foods can be significant.

So, as a policy, we deliberately avoid reporting the source or the condition of the ingredients mentioned in our reviews.

Because of these quality variations, dog food recalls are inevitable… even from the very best companies. No written assurance from any manufacturer (or product reviewer) can ever guarantee safety.

Your best defense? Be sure to check back regularly for all the latest comments, reviews and information about dog food recalls.

And please don’t forget to share what you know about a dog food or a company. Because your knowledge and experience can make a difference.