Acute Toxicity Tests: Acute toxicity studies in mammals are conducted to measure a chemical’s capacity to cause harm or death with a single dose.
Chemicals are administered to animals in extremely high doses via at least two of the following routes:
” Oral — chemicals are pumped directly into the animal’s stomach via a force-feeding tube or syringe.
” Skin — chemicals are painted onto the shaved and abraded skin on the animal’s back.
” Inhalation — animals are either confined in an inhalation chamber or restrained with a breathing apparatus fixed over their mouths.
Acute toxicity studies inflict hideous suffering on animals, who may endure severe abdominal pain; diarrhea; bleeding from the nose, mouth and genitals; convulsions; seizures and paralysis before they are poisoned to death or killed by the experimenter.
Reproduction Toxicology: Reproductive toxicity studies in mammals are conducted to measure a chemical’s effects on reproductive organs and fertility. Such tests are based on a repeated dose toxicity study in rodents, during which animals are examined for changes in sexual behaviour, sperm and egg production and fertilisation, development in the uterus and after birth, and hormonal activity.
At the conclusion of the study the animal’s genitals and reproductive organs are often removed for further study. Animals in reproductive toxicity studies suffer not only from the toxic effects of the chemical under investigation, but also as a result of frequent and often stressful handling, restraint and inhumane force-feeding practices.
Carcinogenicity Tests: Carcinogenicity studies are conducted to measure a chemical’s cancer-causing potential following lifelong exposure. Carcinogenicity studies call for the use of both rats and mice and can kill more than 800 animals per test.
Animals in these studies are exposed to toxic chemicals for their entire lives through their food, their skin or the air they breathe.
Carcinogenicity studies can go on for up to five years, during which animals can endure extended suffering from chemical- poisoning as their bodies are overcome by tumours and cancerous growths.
Repeat dose Toxicology: Repeated dose toxicity studies expose animals to repeated low doses of chemicals for one to three months to measure the effects of multiple chemical exposures on organs such as the liver, kidneys, lungs, heart and nervous system.
Chemicals are usually force-fed to animals orally, although skin and inhalation routes are also used. These studies are typically conducted using two different species of animal, one rodent (rat, mouse, etc.) and one nonrodent (usually dogs). Repeated dose studies are highly stressful and cruel, as animals are subjected to frequent handling, restraint and inhumane force-feeding practices, in addition to suffering the toxic effects of the chemical under investigation.
The animals can suffer excessive salivation, anaemia, muscle weakness, hair loss, internal organ damage, pilo-erection (hair standing on end), vomiting (in dogs), diarrhoea, coma and even death.
Mutagenicity tests: Genetic toxicity (mutagenicity) studies are conducted using a variety of test methods to measure a chemical�s capacity to induce mutations or other changes in the body�s genetic material. Chemicals are force-fed or injected into the abdominal cavities of rats, mice or hamsters. Samples of bone marrow and/or blood are taken at several time points following exposure to the chemical.
Cells are harvested from the blood or bone marrow and analysed for genetic abnormalities. Genetic toxicity studies are highly stressful and cruel, as animals are subjected to frequent handling, restraint and inhumane force-feeding practices, in addition to suffering the toxic effects of the chemical under investigation.
The following is taken from documents produced by the National Anti Vivisection Society when in 1993 an undercover member of NAVS infiltrated the Toxicol complex (now Sequani ltd) by obtaining work as a junior animal technician at the premises.
STANDARD TESTS AND SOME OF TOXICOLS TESTS
Toxicity testing is another name for poison testing. These tests are designed to show the toxic effects of substances that might occur in humans, and also to show the circumstances under which something might act as a poison. They can be acute (short term) tests, or chronic (long term). They are often referred to as ‘safety tests’.
There is a wide variety of tests, and they come in various groupings such as acute, sub-acute, chronic, carcinogenicity, sub-chronic, and so forth. Since we are particularly concerned with acute and subacute tests here, these include:-
 whole body dose ranging or limit setting lethal toxicity tests;
 quantitive whole body lethal toxicity tests
 whole body non-lethal clinical sign toxicity tests; as well as:
 tests for clinical signs in the eye;
 tests for clinical signs on the skin;
 chronic whole body toxicity tests (other than teratogen/mutagen tests);
 teratogen/mutagen tests.
The toxic effects on the animal can include: difficulty in breathing, uncoordinated movement, vomiting, convulsions, tremor, lethargy, coma, behavioural changes, alteration in muscle tone, gastrointestinal disturbances such as diarrhoea, excessive salivation, hair standing on end, excessive secretion of tears, drooping of the eyelids, contraction or dilation of the pupils, discharge or bleeding from eyes or mouth, “unusual vocalisation” (crying out), reddened urine or accumulation of watery fluid in the tissues.
Test substances can include: pharmaceuticals, food and feed additives, pesticides and industrial chemicals, as well as household products, garden products, and personal bodycare products.
In some cases, not only is the toxicity of active agents and suitable solvents tested but also, for example, in the case of pesticides, degradation products, metabolites, and toxic products formed in or on plants.
The species most commonly used are rodents (mice and rats), however the majority of tests must also be carried out on at least one non-rodent mammalian species, usually the dog. Rabbits, guinea pigs, ferrets, cats, ungulates and non-human primates are also used. In the case of substances to be used in the environment tests may also be carried out on birds and fish
Toxicol also undertake research pharmacology which means they use animal ‘models’ of disease to test the effects of new compounds. They can produce animal models for a variety of conditions; bronchopulmonary, anti-inflammatory, cardiovascular, thrombolitic, gastrointestinal and central nervous system. They can also produce new models on request.
Below is a brief outline of the standard safety tests, which would be amongst the range of tests carried out by Toxicol. We have just taken two of the main groupings, acute and chronic testing, and given some examples of tests within those groups.
Although not all of these tests were witnessed by our investigator in 1993, our previous investigation in 1984 revealed that Toxicol had carried out the LD50 test, the Draize eye irritancy test, skin and oral sensitization studies, and chronic toxicity tests.
ACUTE TOXICITY TESTING
Usually the first type of test carried out. A short-term test to find out what occurs when a single dose of the substance is given to a test animal by a variety of routes (e.g. mouth, skin etc). Acute toxicity may be measured by the notorious LD50 (Lethal dose 50%) test; the lethal dose is that single dose that kills half the animals — large quantities of the substance are given to a group of animals until 50% of the group die. Some will die quickly, some will hang on until the end of the test 14 days later.
The substance can also be injected, forced breathing of the vapour, and application of the test substance to the animals’ skin. An average of 60 animals are used and signs of poisoning include crying out, tears, diarrhoea, discharge and bleeding. No pain relief is given. The British Toxicology Society has explained: “there is pressure on the toxicologist to allow the study to continue, even when the animals are in distress, since their killing may alter the end-point of the study, and so possibly affect the classification of the material being tested”.
Other acute toxicity tests are those on the skin and eyes. The standard eye irritancy test involves applying the test compound to one eye of a laboratory rabbit, and watching for damage for up to seven days. The animal is clamped in stocks, and cannot rub the eye to remove the material, or alleviate any pain. Because rabbits cannot produce tears effectively, the eye will not wash the substance away. Shampoos, pesticides, weedkillers, household detergents, riot control gases, industrial chemicals and many other products are tested in this way. This test has been criticised not only for its cruelty, but for the subjective scoring system, where lab technicians might disagree on what is a severe irritant and what is a mild and moderate irritant, and also because of the species differences between the rabbit and human eye.
The skin irritancy usually involves either rabbits or guinea pigs. The animals’ hair is shaved off, and the skin abraded to sensitise it. Abrasion can be by stripping off layers of skin by repeated application of sticking plaster, or the skin can be sensitised by injection. The test material is applied in a variety of ways, and left on the animals’ skin for up to 7 days.
TOXICOLS EXPERIMENTS ON DOGS
Toxicol experiments were coded with a combination of letters and numbers. The number refers to how many studies the client has had with Toxicol, and the first three letters represent the customers’ name. For example study COS/44/C would be the 44th study commissioned by Confarma.
Very little information was provided on the experiments, all were cited as Maximum Tolerated Dose studies but compound names were coded. In two instances, KIR/7/C and PFB/1/C, the compound was identified and so these have been examined in greater detail.
Dosing was by inch long capsules forced down the dogs’ throat, by hand. Another method was gavage dosing, whereby a tube was forced down the animals’ throat and the test substance poured down it directly into the animals’ stomach. Our investigator held dogs for this procedure on two occasions.
At the conclusion of each study, the dogs were killed by an injection of phenyl barbituate.
UHS/1/C: study for the Spanish company Uriach & CIA SA, compound coded. 24 dogs were used in this study. They were killed on 7th June and sent to the Necropsy Department. The study had previously been done on animals in Russia, but not to the standards of Good Laboratory Practice (GLP), and so more animals were having to suffer.
COS/43/C: study of a coded compound for Swedish company Confarma. When the investigation started, this was using 6 dogs. By 10th May two dogs had been killed. On 31st May, our investigator had to hold the surviving dogs during routine blood sampling. The animals’ necks were shaved to make access to the main artery simpler and blood was drawn off by syringe. Blood was taken every thirty minutes for eight hours. The dogs struggled during the bleeding and had to be held very firmly. In the early stages of the study, the test compound had increased the dogs’ pulse rates.
COS/44/C: Another coded compound for Confarma. 32 dogs were used.
KIR/7/C: ETHOFUMESATE: a study of the herbicide ethofumesate for a Finnish agrochemicals company, Kemira. At the start of our investigation on 13th April 1993, the study was using eight dogs, by 10th May two of the dogs had been killed. On 17th May and 2nd June our investigator held the dogs whilst they had a galvage dose. A tube was forced down their throat by another worker; the liquid herbicide, suspended in lactose, was then poured down the tube. Initially, the herbicide had been delivered in capsule form, but so many capsules had been required for each dog (5 or 6), that the dosing method was changed.
AIR POUCH EXPERIMENT: It is rare for commercial testing laboratories to publish scientific papers. However, in 1990, three Toxicol researchers joined with others at the University of Bath and at CIRD, France to publish a study of anti-inflammatory drugs. They employed the air pouch technique, and although they didn’t give details of how they raised the air pouches, this common technique was witnessed by a NAVS investigator at St.Bartholomew’s hospital in 1991.
We sent a copy of our observations of the 1991 experiments to the home secretary’s animals procedures committee, and various MPs. The raising of the air pouches was described thus: “Air is injected under the skin just behind the shoulder blades forming a pouch, and then an irritant, croton oil, is added to it to exacerbate the inflammation…. As the pouches get bigger and bigger, they begin to fall over to one side of the animals’ body. Sometimes they rupture which causes great pain and the animals have to be put down”.
Many thanks to NAVS for sending the documentation concerning their Toxicol report.
NAVS also have a section regarding Toxicol on their site. Please click here to visit
On Sequani’s website, acute toxicology, repeat dose toxicology and carcinogenicity tests are noted as part of their current practice along with other sections dealing with animal experimentation.