Ending toxicity testing on animals.
Suffering on a global scale.
Every year, millions of animals — including pigs, rats, rabbits, dogs and monkeys — are used in toxicity testing worldwide.
Animals are deliberately exposed to substances to see what harm they cause, at what dose, and to which parts of the body. These tests underpin the approval of medicines, chemicals and other products, and remain embedded in regulatory systems globally.
Before new drugs can be tested in people, regulators typically require data from two species — usually a rodent and a non-rodent such as a dog or primate — a system few people ever see and one that comes at a profound cost to animals.
Inside toxicity testing labs.
Animals used in toxicity tests can be subjected to invasive procedures and prolonged confinement and stress, sometimes over months or years. But the impact of this system doesn’t end with them — it extends to the people involved and to the reliability of the results it produces. Here’s a glimpse into what happens inside toxicity testing labs.
Oral dosing (gavage)
Animals are restrained as a long tube is forced down their throats and the test substances are injected directly into their stomachs.
Forced inhalation
Animals are immobilised in restraint devices with a mask strapped to their faces — or inside plastic tubes inserted into an inhalation tower —and forced to breathe in test drugs and chemicals.
Continuous infusion
Test substances are continuously injected directly into the bloodstream of animals.
Dermal toxicity
Test substances are applied to open wounds — rectangles of skin and flesh that are surgically cut out of the backs of pigs. These wounds are immensely painful.
Restraint and immobilisation
Fully conscious rabbits and rats are squeezed into narrow restraint containers that have been designed and manufactured for the purposes of toxicity testing.
Laboratory housing and confinement
Animals in laboratories spend their lives in confinement; usually denied space, exercise and meaningful enrichment.
Human suffering
Technicians carry the emotional burden of harming animals as part of their daily work. Studies show that this “caring–killing paradox” can lead to moral distress, PTSD-like symptoms and depression.
Flawed science
90% of new drugs that pass animal tests fail in human trials. Relying on animals has sent medical research down costly, misleading paths, delaying real breakthroughs that could have come from humane and human-relevant research.
Chosen for their gentle, compliant nature, beagles are tied up and fitted with full-face gas masks that deliver test chemicals into their bodies — they have no ability to resist or escape.
Image Credit:
Toxicity.inc
Completely immobilised in 'inhalation towers', rats are forced to breathe in test substances.
Image Credit:
Toxicity.inc
To enable repeated infusion of a test substance, rats undergo surgery to implant a catheter into their tails. A tether device is attached, and they are confined in a glass ‘jar’, that restricts movement and normal behaviour.
During oral gavage, struggling, squealing pigs have to be restrained while a dosing tube is forced down their throats so that the test substance can be injected directly into their stomach — a deeply distressing and invasive procedure.
Primates often show visible signs of panic and distress in being trapped in these restraint devices and being unable to remove the mask strapped to their faces.
These procedures are not incidental to the process — they are fundamental to how toxicity testing is conducted. The suffering of animals is unavoidable. Pain relief is normally withheld because it might interfere with test results.
The case for change.
Beyond the ethical concerns, the reliability of animal toxicity testing is increasingly being challenged.
Animals are not surrogates for humans. Differences in genetics, metabolism, immune systems and physiology mean they often respond to substances in ways that simply don’t reflect human biology. As a result, animal data frequently fails to predict what will happen in people.
This disconnect is reflected in drug development itself: more than 90% of drugs that appear safe and effective in animal studies fail in human trials — often because they prove ineffective or unsafe.
Despite this, animal testing remains embedded in regulatory systems that have yet to fully catch up with modern science.
But change is underway.
Human-relevant technologies — including organoids, organs-on-chips and advanced computational models — are already transforming how safety can be assessed. These methods are often faster, cheaper and more accurate.
While animal testing for cosmetics is banned in many parts of the world, testing pharmaceuticals and chemicals on animals is still widespread. However, governments in the UK, European Union and United States are now advancing policies to reduce and replace animal testing with more accurate, human-based approaches.
A safety system built on human biology has the potential to better protect people — while preventing immense suffering for animals.
