Animals in the United States are protected by a patchwork of federal and state laws, each targeting a specific type of harm or a specific group of species. No single law covers all animals in all situations. Instead, protections depend on whether the animal is a pet, livestock, wildlife, a marine mammal, or used in research. Here’s how the major laws work and what they actually require.
The Animal Welfare Act
The Animal Welfare Act is the broadest federal law governing the treatment of animals in captivity. Enforced by the USDA’s Animal and Plant Health Inspection Service, it sets minimum standards of care for animals bred for commercial sale, used in research or teaching, transported commercially, or exhibited to the public. That last category includes zoos, which must pass APHIS inspections to maintain their licenses.
The law covers dogs, cats, nonhuman primates, guinea pigs, hamsters, rabbits, and most other warm-blooded animals used in these settings. Its exclusions are significant, though. Farm animals raised for food or fiber are not covered. Neither are birds, rats, or mice bred specifically for research, which represent the vast majority of laboratory animals. Horses are only covered when used for research. So while the AWA is often cited as the cornerstone of animal protection in the U.S., it leaves out the animals most commonly used and killed.
The PACT Act: Federal Animal Cruelty Law
For most of U.S. history, animal cruelty was prosecuted only at the state level. That changed in 2019 with the Preventing Animal Cruelty and Torture Act. The PACT Act makes it a federal crime to intentionally crush, burn, drown, suffocate, or impale an animal, or to engage in other forms of serious physical harm. It also criminalizes creating or distributing videos of animal crushing through interstate commerce. Violations carry a prison sentence of up to seven years, a fine, or both.
The law fills a gap that state laws couldn’t reach, particularly when cruelty crosses state lines or occurs on federal property. It doesn’t replace state cruelty statutes but gives federal prosecutors a tool when jurisdiction is an issue.
State Cruelty Laws and Felony Penalties
Every U.S. state has its own animal cruelty statute, and all 50 now classify at least some forms of animal cruelty as a felony. The specifics vary widely. Most states distinguish between simple cruelty (neglect, failure to provide food or shelter) and aggravated cruelty (intentional torture or killing), with felony charges reserved for the more severe acts.
Common exemptions appear across nearly every state law. Lawful hunting and trapping, accepted veterinary practices, scientific research governed by recognized standards, herding of domestic animals, and standard agricultural processing are typically carved out. Louisiana’s statute offers a window into how specific these exemptions can get: it even exempts chickens used in traditional rural Mardi Gras parades. These exemptions reflect ongoing tension between animal protection and industries that depend on animal use.
The Endangered Species Act
The Endangered Species Act protects wildlife at risk of extinction. Under Section 9, it is illegal for anyone in the U.S. to “take” an endangered species of fish or wildlife. “Take” is defined broadly to include harassing, harming, pursuing, hunting, shooting, wounding, killing, trapping, capturing, or collecting. It is also illegal to import, export, sell, or transport endangered species in interstate or foreign commerce.
Threatened species (one step below endangered) receive protections through separate regulations that the U.S. Fish and Wildlife Service tailors to each species. Endangered plants get a narrower set of protections: it’s illegal to remove them from federal land, destroy them maliciously on federal land, or collect them anywhere in violation of state law. The difference matters because plant protections on private land are much weaker than those for animals.
The Marine Mammal Protection Act
Whales, dolphins, seals, sea otters, manatees, and all other marine mammals are protected under the Marine Mammal Protection Act, which makes it illegal to harass, hunt, capture, or kill any marine mammal in U.S. waters. The law defines two levels of harassment. Level A harassment is any act that has the potential to injure a marine mammal. Level B harassment covers acts that could disturb but not injure, including disrupting migration, breathing, nursing, breeding, feeding, or sheltering.
This means that feeding wild dolphins, chasing whales with a boat, or even getting too close to a seal on a beach can constitute a federal violation. NOAA Fisheries enforces the law and can issue permits for limited exceptions, such as scientific research or incidental harm from activities like commercial fishing, but the default is a blanket prohibition on any interference.
Livestock Protections During Slaughter and Transport
Two federal laws specifically address the treatment of farm animals during their final hours. The Humane Methods of Slaughter Act requires that livestock be rendered unconscious before being killed. Stunning must produce immediate unconsciousness, whether through electric current (which must achieve surgical anesthesia, a state where the animal feels no pain) or a captive bolt device. If a federal inspector witnesses inhumane handling, they can shut down the offending equipment or area by tagging it “U.S. Rejected” until the problem is corrected. A major limitation: poultry is not covered, which excludes the roughly 9 billion chickens and turkeys slaughtered annually in the U.S.
The Twenty-Eight Hour Law governs what happens during transport. Livestock being shipped across state lines cannot be confined in a vehicle for more than 28 consecutive hours. After that, they must be unloaded for at least 5 consecutive hours and given access to feed, water, and rest before the journey continues.
The Horse Protection Act
The Horse Protection Act targets a specific form of abuse called “soring,” which is the deliberate infliction of pain on a horse’s legs or hooves to produce an exaggerated high-stepping gait prized in certain show rings. Soring methods include applying chemical irritants like mustard oil or diesel fuel to the legs, attaching overweight chains, or trimming hooves down to expose sensitive tissue. The law bans sored horses from being shown, exhibited, sold, or auctioned, and APHIS enforces compliance through inspections at horse shows and sales.
Service Animal Protections Under the ADA
The Americans with Disabilities Act protects the right of people with disabilities to bring service animals into public spaces. Since 2011, only dogs qualify as service animals under the ADA (with a narrow exception for miniature horses in some cases). The dog must be individually trained to perform a specific task related to the handler’s disability, such as guiding a person who is blind, alerting someone to a seizure, or retrieving objects. Dogs that provide only emotional support or comfort do not qualify.
Businesses and public facilities can ask only two questions: whether the dog is a service animal required because of a disability, and what task it has been trained to perform. They cannot ask about the person’s disability, request medical documentation, demand proof of training, or ask for a demonstration. A service animal can only be removed if the dog is out of control and the handler isn’t correcting the behavior, or if the dog isn’t housebroken.
Shifting Rules on Animal Testing
Federal law has historically required animal testing before new drugs could be approved for human use. The FDA Modernization Act 2.0 changed that by removing the mandate that drugs must be tested on animals before human clinical trials. Drug companies can now use alternative methods to demonstrate safety.
The FDA has taken this further by announcing plans to phase out animal testing requirements for monoclonal antibody therapies and other drugs. The agency is encouraging the use of AI-based toxicity models, lab-grown cell lines, and organoid testing as replacements. Companies that submit strong safety data from non-animal methods may receive streamlined review. The FDA plans to launch a pilot program allowing select drug developers to use primarily non-animal testing strategies. Implementation for new drug applications has already begun, with the agency updating its guidelines to formally accept data from these alternative methods.