Regulatory Collision: 14 U.S. States Have Laws That Directly Conflict with AAFCO Pet Food Definitions, Threatening Industry-Wide Disruption

By Investigative Reporting Desk
Published in Partnership with Pet Food Consumer Advocacy Groups

Main Facts

A major regulatory crisis is brewing at the intersection of state legislation and national feed control. According to recent findings brought to light by prominent pet food consumer advocate Susan Thixton, statutes in 14 U.S. states directly conflict with the official ingredient definitions established by the Association of American Feed Control Officials (AAFCO).

If legally challenged in a court of law, these glaring contradictions could result in judges declaring many commonly utilized pet food ingredients legally invalid within those jurisdictions. Without a valid legal definition under state statute, these ingredients could effectively be banned from commercial pet foods manufactured, distributed, or sold within the affected states.

The core of the dispute centers on how animal-based ingredients—such as meat meals, by-product meals, and animal digests—are defined, sourced, and regulated. While AAFCO’s model definitions permit the use of non-slaughtered and potentially diseased or decomposed animal tissues under broad federal compliance umbrellas, state commercial feed laws explicitly classify such materials as adulterated.

This legal friction exposes a precarious vulnerability in the American pet food supply chain. Manufacturers, ingredient suppliers, and millions of pet owners now face the looming threat of sudden regulatory enforcement actions, supply chain halts, and widespread market confusion.

Chronology of a Regulatory Oversight

The disconnect between state feed laws and AAFCO guidelines is not an overnight development; it is the result of decades of administrative divergence in how animal feed and pet food are regulated across the United States.

• Mid-20th Century to Present: AAFCO functions as a voluntary membership association of local, state, and federal agencies charged with regulating the sale and distribution of animal feeds and pet foods. While AAFCO establishes model regulations and ingredient definitions, these definitions carry no direct force of law until adopted individually by state legislatures or departments of agriculture.
• Establishment of State Feed Laws: Over decades, individual states enacted comprehensive commercial feed statutes designed to protect livestock and companion animals from adulterated, filthy, or diseased feed components. These laws were modeled heavily on human food safety paradigms, strictly prohibiting the remains of animals that died other than by slaughter.
• The Evolution of AAFCO Definitions: Concurrently, AAFCO committees—comprised of state regulators, federal officials, and industry representatives—crafted modern ingredient definitions for the rendering industry. Over time, these definitions evolved to encompass various animal by-products, permitting broader sourcing parameters while inserting broad qualifiers like "suitable for use in animal food."
• Recent Consumer Advocacy Investigation: Recognizing the widening gap between strict state statutes and permissive AAFCO definitions, pet food safety advocates conducted a state-by-state statutory audit. They identified 14 states where existing laws flatly contradict federal-level AAFCO definitions.
• Formal Notice to AAFCO: Advocacy representatives formally contacted AAFCO leadership, laying out the exact statutory conflicts, naming the 14 states involved, and demanding immediate administrative action to revise ingredient definitions before litigious challenges disrupt the market. At the time of reporting, industry stakeholders await a formal response.

Supporting Data and Jurisdictional Analysis

To understand the severity of the legal exposure, one must examine the specific mechanics of state statutes compared against AAFCO’s terminology. The 14 states identified as having direct statutory conflicts with AAFCO definitions are:

1. Arkansas
2. Colorado
3. Connecticut
4. Florida
5. Idaho
6. Indiana
7. Kentucky
8. Michigan
9. Minnesota
10. Mississippi
11. Missouri
12. Montana
13. New Mexico
14. North Dakota

The Missouri Case Study

Missouri serves as a clear blueprint for how these statutory conflicts manifest in a court of law. Under Missouri Revised Statute Section 266.180 (Adulterated feed, what constitutes), state law dictates:

"A commercial feed shall be deemed to be adulterated: (i) If it is, in whole or in part, the product of a diseased animal or of an animal which dies other than by slaughter which is unsafe within the meaning of section 402(a)(5) of the Federal Food, Drug, and Cosmetic Act…"

Furthermore, Missouri law establishes that a commercial feed is adulterated "If it consists in whole or in part of any filthy, putrid, or decomposed substance, or if it is otherwise unfit for feed."

The AAFCO Conflict

In direct contrast, standard AAFCO definitions for several foundational pet food ingredients—including Poultry By-Product Meal, Poultry By-Products, Meat Meal, Meat and Bone Meal, Animal By-Product Meal, and Animal Digest—do not mandate that the source animals be slaughtered for human consumption. Without an explicit slaughter requirement in the text of the definition, ingredient manufacturers operate with the legal leeway to utilize non-slaughtered, dead-on-arrival (4D) animals.

To bridge this gap, AAFCO includes the sentence "It shall be suitable for use in animal food" across its animal product definitions. AAFCO defines "suitable" as conforming to the Federal Food, Drug, and Cosmetic Act unless an appropriate agency permits otherwise.

However, under administrative law principles—such as Missouri Revised Statute Section 536.014, which states that "No department, agency, commission or board rule shall be valid in the event that… The rule is in conflict with state law"—administrative definitions cannot override explicit state statutes. If a plaintiff or competitor challenges an AAFCO-derived ingredient definition in a Missouri court, the judiciary is legally bound to strike down the definition as invalid because it permits diseased and decomposed animal matter explicitly banned by the legislature.

Because all 14 listed states maintain comparable statutory language regarding adulterated feed, dead animals, and filth, the legal vulnerability is systemic rather than isolated.

Official Responses and Industry Implications

The revelation that regulatory officials from these 14 states have actively participated in—and even chaired—AAFCO Pet Food and Ingredient Definitions committees while their home state laws outlawed the very definitions they helped draft has sparked intense industry criticism.

The Regulatory Dilemma

Regulatory bodies now face an uncomfortable paradox:

• If state regulators enforce AAFCO definitions, they may be acting in direct violation of their own state statutes, opening state agencies up to legal challenges from consumer groups or competing agricultural sectors.
• If state regulators uphold state statutes, they must invalidate AAFCO definitions within their borders, rendering standard pet food formulations technically illegal overnight.

Consumer and Market Impact

For pet food manufacturers, the ramifications are profound. Compliance officers must evaluate whether their supply chains in Arkansas, Florida, Michigan, and the other 11 jurisdictions rely on ingredients whose legal definitions rest on shaky constitutional ground. A single successful lawsuit in any of these states could trigger nationwide ripple effects, forcing reformulations, halting distribution channels, and driving up production costs.

Pet food consumer advocates are pressing AAFCO to take immediate corrective action. The demands placed before AAFCO leadership include:

• Immediate acknowledgement of the statutory discrepancies.
• Comprehensive revision of all Animal Product ingredient definitions to ensure absolute alignment with state laws.
• Mandatory incorporation of explicit requirements stating that pet food ingredients must be sourced exclusively from slaughtered, disease-free animals that are entirely free from filth and decomposition.

Conclusion

The collision between AAFCO ingredient definitions and state commercial feed laws is no longer a theoretical debate—it is an active legal time bomb sitting beneath the commercial pet food industry. With 14 states maintaining statutes that flatly invalidate standard rendering definitions, the current regulatory framework is untenable.

As consumer advocates await a formal response from AAFCO, the onus falls on state legislators, regulatory bodies, and pet food manufacturers to address these structural contradictions. Until AAFCO definitions are harmonized with state laws, the legal legitimacy of everyday pet food ingredients remains hanging in the balance, threatening transparency, consumer trust, and market stability across the United States.