FAQs About Animal Testing


Is animal testing the only way to make sure products are safe? What happens to animals killed after they're used in testing? DoSomething.org asked Nancy Beck, Ph.D. and Science and Policy Adviser at Physicians Committee for Responsible Medicine, to answer such frequently asked questions.

Which animals are most vulnerable to animal testing?

Mice and rats are the most commonly used animals for both toxicity testing (testing ingredients and products on animals to determine whether they are safe for humans). For toxicity testing, other animals commonly used include rabbits, guinea pigs, hamsters, gerbils, dogs, sheep, pigs, fish, frogs, cats, and monkeys.

How are the animals used or tested?

  1. An animal is exposed to a test substance, either by being forced to eat it, breathe it, have it rubbed on their skin, or have it injected. The test substance is often a household chemical, an industrial chemical, such as a pesticide, a food additive, a cosmetic ingredient, or a pharmaceutical product.
  2. Animals are observed for toxic effects such as vomiting, diarrhea, convulsions, respiratory distress, appetite or weight loss, rashes and allergic reactions, skin and eye irritation, salivation, paralysis, lethargy, bleeding, tumors, birth defects, and many other harmful effects.
  3. Animals are then killed to end the experiment, worse still, their internal organs are often examined for harmful effects.

Depending on the specific type, tests can vary in duration from a few hours to several days or months.

A few specific examples of common toxicology tests include:

  • Reproductive and developmental toxicity test: Rats or mice are exposed to a test substance and bred. After the animals give birth, the adults are killed so that their reproductive systems can be examined. The offspring are examined for birth defects and are also eventually killed.
  • Acute toxicity test (LethalDose50): Animals, usually rodents or dogs, are fed a test substance in increasing quantities to find out how much is required to kill them.
  • Skin irritation test (Draize test): The test substance (often an acid or painful substance) is rubbed onto a rabbit’s skin to see if it causes irritation.
  • Inhalation toxicity test: Rats are either placed in sealed cages or squeezed into restraint tubes pumped full of gas, forcing the animal to breathe in the vapors of the test substance, usually for 4-6 hours/day for either one-day, several weeks, or months. Animals are examined to determine whether breathing the substance has toxic effects.
  • How often are animals euthanized or killed after completing their testing?

    The majority of animals used in toxicity tests are killed at the end, often, so their internal organs can be examined. The way animals are killed can vary, but the most common methods are asphyxiation (forcing them to inhale a deadly gas, such as carbon monoxide or carbon dioxide), decapitation (beheading) and cervical dislocation (breaking the neck or spine).

    Why can’t most animals be put up for adoption after they’re testing is finished?

    Animals are often killed as part of the test, in order to determine whether there has been any toxicity to their internal organs.

    Is it an option for scientists to conduct their experiments without using animals?

    Yes. Many alternatives are now available, and more are being developed. These methods are based on the human body and can produce more accurate information. They are also much faster and cheaper than using animals. These non-animal test methods involve using human cells and tissues that can be grown in the lab, as well as building computer models to predict test results based on existing data from other similar substances.

    Are there humane ways to conduct testing?

    No. Animals that normally live in groups can experience social isolation because they are often housed alone in cages for testing. Since animals are usually forced to live in small cages, they also lose the ability to fulfill natural behaviors like chewing, digging, and exploring.

    Are animal welfare laws effective in preventing scientists from treating their subjects cruelly?

    Unfortunately, no. The only federal law that applies to animals used for testing is the Animal Welfare Act, which only regulates cage size, cleanliness, and food and water, but does not limit the procedures that can be performed. This law excludes rats, mice, birds, cold-blooded animals, and animals commonly killed for food—so rats and mice, the animals most commonly used in toxicity tests, are not even given minimal protections.

    There’s also animal testing in schools—you've heard of frog dissection in anatomy class. Are there better methods to learn about anatomy that don't involve dissecting animals?

    With today’s wide selection of high-quality alternatives, students of any age can learn without sacrificing kindness to animals. Students who use non-animal alternatives also gain an educational advantage, as studies have repeatedly shown that alternatives are a superior teaching method to traditional dissection.