Animal By-Products in Dog Food – What's Really Behind Them?
By Mutti | Updated May 2026
You're standing in front of the shelf, turning a bag of dog treats in your hand. On the front, it says "Premium" and "made with real meat." On the back, you read "meat and animal by-products." At that point, your mood usually shifts from interested to suspicious. And rightly so. Because animal by-products in dog food are one of the most important yet flexible categories in feed law.
In short: Animal by-products in dog food are a legally defined collective term from EU feed law. This includes valuable parts like liver, heart, and tripe, as well as nutritionally useless material like feathers, claws, or hooves. The term alone, therefore, says little. What matters is whether the animal species is named, which components are listed, and whether quantities are specified. This logic applies to main feed as well as to treats – and for treats fed multiple times daily, paying close attention is especially worthwhile.
What Animal By-Products in Dog Food Legally Are
The term comes from EU feed law, specifically Regulation 767/2009 and Regulation 1069/2009. Animal by-products are all animal components not intended for human consumption but permitted for animal feed. They are divided into three categories: only material from Category 3 may be used in pet food and dog treats. Categories 1 and 2 (diseased animals, higher-risk material) are strictly prohibited and must be disposed of.
So much for the legal side. In practice, this means: If you read "animal by-products" on a package, the material is generally K3 and therefore hygienically safe. That's the good news. The bad news: K3 is a very broad category. It includes both nutrient-rich offal such as liver, heart, lungs, kidneys, and tripe, as well as significantly less valuable components such as feathers, hair, claws, hooves, hides, or blood. All of these can legally fall under the same collective term.
This is precisely the real problem. Not with the term itself. But with the fact that it treats very different qualities equally.
Why Animal By-Products Have a Bad Reputation
The bad reputation doesn't come out of nowhere. Many owners read "by-products" and immediately think of waste. That's an oversimplification, but understandable – the term sounds technical, unappetizing, and above all, imprecise.
Added to this is a reality prevalent in the feed industry: a closed declaration can conceal a highly variable composition. Today more liver, tomorrow more lung, the day after tomorrow feather meal. This is legally permitted as long as the animal species group (e.g., "poultry") remains the same. For healthy dogs, this doesn't automatically have to be a problem. For owners who want to feed specifically, it's still a real problem – comparability is completely lacking.
I don't approve of manufacturers suddenly becoming vague in their ingredient lists. If something sensible is processed, it can also be named. "Beef heart" is information. "Animal by-products" is just a category.
Organs Are Included – Feathers Are Too
Here, it's worth distinguishing between the term and quality. Offal is classic animal by-product, but neither worthless nor fundamentally inferior to muscle meat. On the contrary:
- Liver provides high amounts of Vitamin A, iron, and B vitamins
- Heart contributes coenzyme Q10 and muscle protein – essentially muscle meat with a bonus
- Kidney contains relevant micronutrients like selenium and zinc
- Tripe provides digestive enzymes and is well-tolerated by many dogs
- Lungs are rich in protein and lean
Anyone who adheres to the prey animal principle knows: A prey animal doesn't just consist of muscle meat. Organs are not nutritionally a waste bin, but part of a complete utilization of the animal.
On the other hand, there are components that also fall under "animal by-products" legally, but contribute little to nothing nutritionally. Feathers and hair consist of keratin, which dogs can hardly digest. While they provide crude protein – values that look good on the label – they offer hardly any usable amino acids. The same applies to claws, hooves, and highly processed hides. The animal ingests these substances, but the body can do little with them.
Precisely this variability makes the term so problematic. A snack with 30 percent tripe and heart is nutritionally completely different from a snack with 30 percent feather meal. On the label, both might simply say "animal by-products."
The Same Logic Applies to Snacks – Only More Important
If your dog eats main food, they usually do so twice a day. Active dogs, however, can quickly get ten, twenty, or more snacks a day. Every single reward during training, every piece during a walk, every chew experience in the evening on the couch.
This means: For snacks, the ingredient quality adds up even more significantly than for main food. Anyone who regularly feeds undefined by-products throughout the year is distributing a black box over thousands of meals. Those who rely on clearly declared ingredients for snacks do not have this risk.
That's why I find the question of animal by-products in snacks even more urgent than in main food. For a daily training snack, I want to know exactly what's in it – not because a single snack would be a problem, but because when fed frequently, the sum matters.
Mutti-Moment: The Training Treat I Threw Out
At a dog school, small, semi-soft training treats were once handed out. Emil liked them, and I was initially relaxed – small pieces, smelled reasonable, everything okay. At home, I turned the bag over: "Meat and animal by-products, cereals, vegetable by-products, sugar, glycerin." No animal species. No quantity. No breakdown.
I threw the bag out. Not out of drama, but because I simply can't make sense of such a list. With Emil, I do it this way: If I can't trace an ingredient back to a reasonable statement, it's out of the selection. I would proceed the same way with main food.
This is not dogma, but practice. Anyone who observes their dog for a longer period – digestion, skin, coat, energy – knows that clarity in the bowl later brings clarity in classification. With a closed declaration, I don't know if my dog reacts to liver or to feather meal. That makes any observation worthless.
Three Forms of Declaration – What You Need to Know
EU feed law permits three ways to label ingredients on dog food and dog treats. This is the most important information for understanding labels.
| Declaration Form | What it states | Example |
|---|---|---|
| Open Declaration | All ingredients individually named with animal species and percentage | 95% horse (muscle meat, heart, liver) |
| Semi-Open Declaration | Main ingredient named, components partly listed, quantities often vague | Beef (muscle meat, heart, liver), rice, carrot |
| Closed Declaration | Only collective terms without animal species or components | Meat and animal by-products, cereals, vegetable by-products |
All three forms are legally permitted. But they are not equally informative. Open declaration is what you want as a conscious owner. Closed declaration is what many manufacturers prefer because it allows them flexibility in the recipe.
Beware of the 4 Percent Rule
A trap many owners don't know: If an ingredient is highlighted on the front, such as "with chicken," an amount of only 4 percent is sufficient according to EU regulation. The remaining 96 percent can come from completely different animal species or components. If you read "dog food with lamb" or "snack with beef" and think it largely consists of that animal species – no. It might be as much as a teaspoon per package. This is one of the most important things you should know when reading dog food labels and snack packaging.
How to Recognize a Usable Ingredient List
You don't need to have studied feed analysis. A few points are often enough to properly classify labels.
| What to look for | More transparent | Rather unclear |
|---|---|---|
| Animal species | clearly named, e.g., beef or chicken | only "animal" or generally "poultry" |
| Components | heart, liver, tripe, neck named | no breakdown |
| Quantity information | understandable percentage shares | none or very rough information |
| Recipe logic | ingredients appear consistent and constant | collective terms, interchangeable |
| Comparability | clearly recognizable between varieties | hard to assess |
| 4 percent trap | no advertising with tiny proportions | "with chicken" on the front, no quantity specified |
If you stand in front of a package and have more questions than answers after reading it, that's rarely a good sign. Not because something bad is automatically in it. But because transparency is lacking.
When Animal By-Products in Dog Food Can Be Useful
They are useful when they are incorporated as defined components into a traceable recipe. Organs are part of a balanced diet for many dogs. They provide nutrients like Vitamin A, iron, zinc, selenium, and coenzyme Q10, which pure muscle meat does not cover in the same way. For this reason, in a calculated BARF diet, organs are specifically included.
Also, from the perspective of resource utilization, the use of various animal components is sensible. If an animal is used for nutrition, it is more logical not to use only the "noble" parts. This also has to do with respect for the animal and not just with calculation.
The crucial point remains: useful does not mean arbitrary. A recipe consisting largely of unspecified animal by-products is different from a clearly declared composition with defined offal.
Where You Should Look More Closely
I become suspicious of three things: first, very general collective terms without animal species; second, changing components without clear labeling; and third, recipes that sound like they contain a lot of meat on the label but only indirectly reveal what's actually in them.
I'm particularly skeptical of terms like "animal protein" or "meat meal without animal species." This is usually a signal that the recipe is kept flexible. Today chicken, tomorrow beef, the day after tomorrow whatever is cheaper. Not automatically a problem for healthy dogs. But it is for owners with sensitive dogs or those who desire consistency.
What the Declaration Doesn't Reveal – and What Still Matters
Even a good ingredient list doesn't answer everything. The quality of a dog food or treat also depends on raw material quality, processing, storage, and nutrient balance. A clearly named liver is not proof of a well-rounded product. Conversely, a recipe is not worthless just because the term "by-products" appears – if the components are specifically named, it can be perfectly fine.
So you have to consider two levels simultaneously. First: What exactly is on the label? Second: Does the overall composition make sense for the purpose? A training treat doesn't have to meet the same standards as a complete food, but it should still be clearly declared.
How to Read the Term Without Panic, But with Understanding
When you read "animal by-products" in dog food, it's best to ask yourself three simple questions. Which animal species is meant? Which specific components? And does the brand voluntarily state this clearly or does it hide behind collective terms?
If these questions are answered properly, the term can be completely unproblematic. If not, you don't have to panic immediately – but you can be skeptical. Skepticism is often healthier than blind trust when it comes to food and treat labels.
I like ingredient lists that read like factual information, not like a negotiation. Especially when feeding consciously, you don't want a guessing game.
Frequently Asked Questions About Animal By-Products in Dog Food
Are animal by-products in dog food bad?
No, not automatically. The term includes both nutrient-rich offal like heart, liver, or tripe, as well as nutritionally worthless material like feathers, claws, and hooves. It becomes problematic primarily when it remains unclear which animal species and which components are actually contained.
What counts as animal by-products in dog food?
This includes offal (liver, heart, lungs, kidneys, tripe), bone parts, cartilage, tendons, but also feathers, hair, hooves, claws, hides, and blood. All these components can legally appear on the label under the same collective term "animal by-products," although they are nutritionally extremely different.
Why do manufacturers only write "animal by-products" and not the exact ingredients?
Because EU Regulation 767/2009 allows such a closed declaration. For manufacturers, this is flexible – they can adapt the recipe by batch. For you as an owner, it is not very informative because you don't know what your dog is actually eating.
Are open declarations better for dog food and treats?
For classification, almost always yes. If the animal species, components, and percentages are named, you can understand and compare the recipe much better. This does not automatically make a product perfect, but at least verifiable.
Are offal in dog food the same as inferior slaughterhouse waste?
No. Offal are classic animal by-products, but often nutritionally valuable. The term "slaughterhouse waste" is often used generically in everyday language but is too crude. Only material from Category 3 (material fit for human consumption) may be used in pet food and treats according to EU law.
Does this also apply to dog treats?
Yes, exactly. The same regulation applies to treats and main food alike. For treats, the question is even more relevant because active dogs often get many treats a day. With frequent feeding, the ingredient quality – and thus any sloppiness in the declaration – adds up.
How do I recognize if a treat is clearly declared?
You look for three things: a specifically named animal species (e.g., "horse" instead of just "meat"), a quantity (e.g., "95% horse"), and ideally a breakdown of the components (e.g., "muscle meat, heart, liver"). If all three are on it, you have an open declaration. That's what you want as a conscious owner.
With Dogvanture snacks, you'll find exactly this clarity: one animal species per snack, specifically named, with percentage. Once you've consciously looked at ingredient lists, you'll later wonder why you didn't do it sooner. In the monoprotein range, you'll find snacks where "animal by-products" don't even appear on the ingredient list – because it's simply horse, venison, or beef, clearly named.
Mutti is Emil's home and writes here