Rats (and mice) are often the animals of choice to try and model human conditions, treatment and body functions - even though we know that using animals to try and model people fails over 90% of the time.
Mice and rats are commonly used due to their small size, low maintenance (i.e., they are easy to house and care for), short life cycle, and ability to breed quickly (allowing large numbers to be generated for studies).
They also share many of our genes.1 However, that's not surprising. Even cats share many of our genes.2
Rats are used is some of the most gruesome experiments that involve things like force-feeding, poisoning, oxygen deprivation and invasive surgery.
Rats in NZ have been used for:
- Drug research, including safety and efficiency testing.
- Teaching purposes in schools, mainly dissections.
- Investigating ways of killing wild rats. (i.e., research into effective poisons and traps).
- Medical research, including research into the development of severe diseases (i.e., stroke, diabetes, cancer), modelling neurological disorders (i.e., Schizophrenia, Autism), modelling mood disorders (i.e., example, anxiety, and depression) and research into tinnitus.
- Drug addiction research including research into the development and suppression of addictions and the impacts of drug use.
- Basic biological research, including research into digestion, aging, nerve damage, obesity and how the brain functions.
Places that use rats for science in NZ include crown research institutes, private companies and universities. In fact, most universities have their own breeding colonies. Otago University states on its website that they have a dedicated rat testing room in the Behavioural Phenotyping Unit.3
Rats used for science in NZ are sourced from breeding units, public or commercial sources, the wild (captured) and they are imported from overseas.
Discover real-life examples of how rats have been used in NZ below!
Studying selenium metabolism
Cats and dogs were fed diets with different selenium supplementation for three weeks in individual metabolic chambers. A liver biopsy was taken under anaesthesia.
Monitoring wild cats via GPS collar
Wild cats were caught and fitted with GPS collars. After an average of 9.75 days, there were recaptured to retrieve the collars.
Testing new toxin against stoats and wild pets
Dogs, cats and stoats were fed different versions of toxic bait. Symptoms and time of death were monitored. Four dogs and two cats survived, but their fate is not stated.
Testing the efficacy and shelf-life of a toxin
Captive wild cats were used to compare the efficacy of different toxin formulations and the effect of more extended bait storage. Cats were fed the toxin bait or pipette-fed toxin directly as control. Symptom onset and time of death were monitored.
Studying the genes for hairyness
The hairiness of male and female cattle was rated. Some animals had their rectal temperature taken repeatedly, and some were shut in a hot room for two hours to make them sweat. Eight calves were killed to take brain samples.
Optimising fertility treatment
Young female cattle were treated with different hormonal injections to control their fertility cycle. Around ten rectal ultrasounds were done on each of them within 11 days, and several blood samples were taken in the next month. All but nine were artificially inseminated. The nine animals showed no fertility signs and were therefore useless for the study and the industry.
Trying out a health test for breeding bulls
Breeding bulls were infected with a skin fungus that usually results in a dangerous build-up in the gall and eczema. Through a special diet, bulls can be tested for their reactions via repeated blood samples and ranked for their genetic quality.
Testing a vaccine against miscarriage
Younger and older pregnant cattle were injected with a new vaccine against a parasite or just control solution. Skin reactions to the injection were checked, and blood samples were taken. Farmers reported miscarriages when they happened, and dead foetuses were collected if possible. If female calves were born, blood samples were taken from them, too.
Studying Johne’s disease
Some female calves of a group were infected with bacteria causing life-threatening sickness. Poo samples were collected directly from the rectum of all calves every other month. Half were killed to be dissected at 7 months, the rest at 15 months.
Studying Johne’s disease bacteria
Blood samples were taken from sick dairy cows who were sent to slaughter to see if their immune system was even putting up a fight. After slaughter, organ samples were taken.
Finding a gene to increase casein in milk
Breeding bulls were evaluated on their quality by judging, breeding, and milking their daughters. No exact numbers are stated how many lived to the end of the study (5 lactations).
Testing a new way to treat liver flukes
Young cattle were infected with liver flukes. They were treated with different medications or left untreated. Regular blood samples were taken from all animals for three weeks, and they were killed ten weeks later.
Studying effects of stunning before slaughter
Calves and sheep were anaesthetised. Some got 70-volt shocks to the shoulder. Others had a nerve exposed and stimulated before being stunned or cutting their throat.
Measuring brain reactions to stunning after killing
Calves were fasted for 24 hours and then anaesthetised. They were killed by their throats being cut, followed by stunning while measuring EEG/ECG (electronic heart and brain activity) and blood pressure.
Measuring brain reactions to stunning
Calves were fasted, anaesthetised and stunned with a non-penetrative bolt while being monitored for their response. After measurements were taken, they were killed.
Studying brain reactions to cutting blood vessels or neck tissue
Calves were anaesthetised, and their throat blood vessels exposed. While monitoring the brain“s activity (EEG) and blood pressure, either only the blood vessels or only the neck tissue was cut. The latter animals were then killed, too.
Measuring if being slaughtered is unpleasant
Calves were fasted, anaesthetised, and killed by cutting their throat. EEG and ECG (recording electronic heart and brain activity) were measured with electrodes in the head.
Measuring brain reactions to pain
Twenty calves were fasted and anaesthetised. Their horn buds were removed with a scoop, and pain response of the heart and brain with and without pain blockers.
Testing mastitis treatments
Dairy cows with an udder infection were treated with different antibiotic injections. Milk samples were taken to monitor results.
Trying to clone cows with more valuable milk protein
The genetic material of a cow foetus was manipulated and cloned into several cows. When they were less than one year old, they were injected with hormones to produce milk for sampling.
Analysing Greyhound race injury statistics
Historical data on Greyhound races between 2014 and 2019 were analysed. Injuries and deaths were investigated.
Using bones of euthanised shelter dog
Cadavers of dogs killed at an animal shelter were donated. Holes were drilled into leg bones and fitted with screws.
Investigating farm dogs for four years
Working farms dogs were examined regularly for four years. Health problems and fate were recorded.
Transplanting faeces as diarrhoea treatment
A dog with diarrhoea was treated with laxatives and warm water before a faeces sample from a healthy dog was inserted into his colon. Samples were taken before and after.
Testing the eyes of working dogs
Eye examinations were performed on working sheep dogs. Medication for pupil dilation was given, and faeces samples were taken from most dogs.
Analysing dog movements
Colony dogs were prepared with reflective markers and an activity collar. Their movements on a treadmill at various speeds were recorded.
Testing the effect of diet on farm dog performance
Working dogs were fed a diet very high or very low in carbohydrates. Their blood glucose and activity were monitored three times over four days each.
Testing a parasite treatment
After a pilot study with just one dog, six more were given an experimental parasitic treatment. Regular blood samples were taken through a catheter.
Teaching dogs to smell out catfish
Five pet dogs were trained over several months to identify catfish and goldfish smell in water samples.
Testing different combinations of pain meds
Eight dogs are treated with four different combinations of the test drugs in random order with two-week breaks in between. Two catheters are placed in leg veins (for drug injection and blood samples). For the test, dogs are fasted for 12 hours and anaesthetised. EEG is recorded with electrodes near the brain to measure response to electric shocks. Regular blood samples are taken for 8 hours.
Studying medical data of cat and dog CT-imaging
Medical data from cats and dogs were gathered, and animals that had been euthanised for other reasons were examined.
Teaching dogs to smell out koi carps (2019)
Three pet dogs were trained over several months to identify koi carb smell in water samples.
Testing working dogs for internal parasites
Faeces and blood samples were taken from working farm dogs.
Testing fluid management of dogs during anaesthesia
Dogs were anaesthetised. Their heart activity was measured while hey were injected with calculated amounts of fluid.
Trying to make rat poison unattractive for dogs
Dogs were fasted overnight and then given two food bowls with different kinds of repellent on one of them.
Surveying respiratory disease in racing Greyhounds
Laboratories sent in serum samples of dogs for analysis. Additionally, 17 racing Greyhounds were tested.
Using fish to study the impacts of Climate Change
Fish were either bought or caught and killed so that they could be dissected.
Overfeeding Zebrafish to learn about obesity
Normal and transgenic zebrafish were fed normally or way too much. The fish were taken out of the water for glucose tests and blood samples.
Studying gut bacteria in fish
Nine fish were caught by underwater spearing and killed so that samples could be collected from their digestion tracts.
Studying the sleep of sharks
Sharks were caught and kept in outside tanks. For the experiments, they weren't fed for at least 4 days, of which they spent 3 days in a measuring chamber not much bigger than the shark. Oxygen consumption and behaviour were continuously recorded for the last 24 hours.
Infecting fish larvae as a potential model for humans
Zebrafish larvae were injected with bacteria to test how their immune system responds. This was repeated to test how well the immune system reacted and how long the effect lasts.
Finding a “growth gene” in snappers
Snappers were caught from the wild and bred. Around eighty-thousand of their offspring were hatched and raised. At regular “grading” events, injured and deformed fish were disposed of. At just under a year old, around twenty-two-thousand were left and transported to a sea pen, where they were raised to 17.5 months old before harvesting.
Testing how much fat you can feed fish
Fish in aquaculture were divided into groups and fed diets with different fat content. Fish were anaesthetised and faeces samples squeezed out of them.
Testing fish for mercury contamination
Wild fish were caught, measured and frozen to be analysed.
Measuring how stress affects fish
Fish were exposed to chronic stress for four weeks, while 57 non-stressed animals were kept as a control. Signs of stress were noted. At the end of the experiment, all were chilled to death.
Exposing fish to herbicides
Zebrafish were kept in tanks that were contaminated with different herbicide concentrations for 10 days. They were then mated to herbicide-exposed or control fish. Both generations were tested on behavioural changes at around 4 months of age. 24 fish per treatment were killed and dissected.
Testing supplements as protection from toxins in over 1,000 fish embryos
Embryos were harvested and kept in Petri dishes for toxicity and treatment tests. Embryos were treated with an antioxidant, a gold salt or both on the first day, and abnormal development was measured on day 5.
Studying effects of drying rivers on mudfish
Water depth and quality were measured at 24 different sites. Several traps for fish and invertebrates were set at 8 visits, sampling and mostly killing the caught animals (including 15 individuals of the endangered Kōwaro).
Studying bacterial spread in fish larvae
Bacteria were genetically modified and made fluorescent. Zebrafish were bred, and their larvae were infected with the bacteria. The fish were killed for analyses or used for live imaging under a microscope (and then killed, most likely).
Investigating effects of invasive fish removal
Using fyke nets and electrofishing, fish were caught on four occasions. Fish were marked with fin clippings around one big removal event where 3 tonnes of fish were caught. In recaptures a week after each marking event, invasive fish caught were killed after the examination.
Studying fish life cycles
Fish were sedated and their blood and ovarian tissue were sampled three times.
Questioning vets on pain management
Veterinarians completed a questionnaire regarding pain and pain management in rabbits and guinea pigs.
Testing nerve reactions to electric stimulation
Young guinea pigs were bled to death. Specific nerves were removed and experimented on.
Studying short-sightedness
Guinea pigs had one eye covered for two weeks before increasing their eye pressure surgically and kill them.
Measuring nerve reactions to gases
Guinea pigs were anaesthetised, and their windpipe and blood vessels were cannulated. They were exposed to different gases and cyanide while measuring breathing and nerve activity.
Studying how anaesthesia affects breathing and heart
Guinea pigs were put in airtight chambers to test the effects of low oxygen. Some were surgically fitted with tubing so blood samples could be taken during the tests. In the end, all were killed.
Studying compensation after inner ear destruction
Guinea pigs were anaesthetised, and their inner ear was destroyed with a drill. Videos were made for over two days of their balance recovery.
Killing pregnant guinea pigs for tissue cultures
Pregnant guinea pigs were anaesthetised at specific time points of their pregnancy, including during labour, to then remove the uterus for tissue culture experiments.
Testing how oxytocin injections cause contractions
Pregnant guinea pigs were surgically implanted with electrodes on or near the uterus. They were injected with oxytocin in specific doses and timeframes, and the effects were measured.
Harvesting testicles for studies
Male guinea pigs were killed with CO2 to remove their testicles for experiments.
Testing a new tuberculosis vaccine
A new tuberculosis vaccine was tested by injecting guinea pigs with the bacteria, either with or without prior vaccination. After several weeks, all were killed.
Testing how heart calcium metabolism is different in species
Guinea pigs and rats were decapitated, and their hearts were quickly removed to study them.
Testing influences on the rate of a dissected heart
Albino guinea pigs were anaesthetised and dissected before they were killed.
Confirming the correlation of energy storage and stress in the inner ear fluid
Guinea pigs were anaesthetised and artificially ventilated. Ear fluid samples were taken through a hole in the skull, while exposing them to noise or lack of oxygen.
Comparing natural and genetically altered tuberculosis strains
Guinea pigs were infected with tuberculosis strains after being injected with bacterial proteins beforehand. In the end, all guinea pigs were killed and dissected.
Comparing effects of anaesthetics on breathing and heart rate
Guinea pigs, rabbits and rats were anaesthetised, and a tube was put into their windpipe through the neck. They were made to breathe anaesthetic gas.
Researching scoliosis genes
Transgenic mice with a specific gene defect were mated. Pregnant mice were at several time points. The unborn babies were taken, skinned, and gutted to stain their skeletons for better pictures.
Studying hormone influences on obesity and fertility
Transgenic mice were bred to have diabetes symptoms. Together with control mice, they were fed a normal or a high caloric diet and compared for their fertility over 150 days.
Testing a new stroke treatment
Mice were squeezed into plastic cones, and test drugs were dripped on their nose. An artificial stroke was caused by injecting a chemical into their brain. Before and after, mice had to perform behavioural tests. All were then killed to take their brains.
Testing another new stroke treatment
Mice were operated on several times. They were made to experience an artificial stroke, were later injected with a possible treatment, and then were injected with a marker. The mice had their memory tested before they were killed.
Testing prostate cancer drugs
Mice were anaesthetised, and their prostate was injected with cancer cells or a control solution. A 42-day treatment course started three weeks later with different treatment drugs and control solutions. In the end, all mice were killed.
Testing a heart attack treatment
Mice were trained to eat jelly and then subjected to an artificial heart attack. They received either a new drug or a control substance. Regular heart ultrasounds were performed before they were killed and dissected.
Studying ovary problems caused by testosterone
Transgenic mice were implanted with a capsule containing either hormones or not. Vaginal smears were done for several weeks, and serial blood tests were performed twice. In the end, all mice were killed.
Testing an Autism treatment on transgenic mice
Mice were genetically modified to show "autism-like" symptoms. Together with control animals, they were either fed normally or with a high-zinc diet. Invasive behavioural tests were performed. At least some, likely all, were killed.
Comparing transgenic mice and humans
Mice were anaesthetised, and their body composition was measured several times. Their grip strength and balance were tested with lab equipment. In the end, all mice were killed.
Testing a new stroke drug for better dexterity
Transgenic mice were anaesthetised, and an artificial stroke was caused. They then received either a test drug or a control solution. After recovery, their food was limited to test their fine motor skills every other week. After two months, they were killed.
Testing migraine drugs
Mice were injected with potential migraine drugs and anaesthetised. Ultrasound imaging of their ears was taken. One ear was rubbed with capsaicin to record the increased blood flow and compare different drugs, doses, and time points.
Killing rats and mice for tissue
Rats and mice were anaesthetised, and their necks were broken. Their tissue was then used for research.
Studying Alzheimer’s and stroke symptoms
One group of transgenic mice were bred and killed at either four or 12 months of age by flushing their hearts. Another group was anaesthetised and caused to have a stroke. They were killed the same way.
Testing Alzheimer’s treatment on mice
Transgenic and “normal” mice were injected with a special protein and a chemical to mark new brain cells that may have been produced.
Testing a new Alzheimer’s drug
Newborn mice were killed to collect brain tissue. Adult mice were used to test drug reactions. They were anaesthetised twice; to inject the drugs and to flush their hearts and take their brains.
Testing if anaesthesia affects the sleep–wake cycle when combined with light treatment
Mice were kept on a 12-hour light/dark cycle and then switched to total darkness. During this time, they were exposed to light once, either with or without anaesthesia. The effect on their activity cycles was monitored. In the end, all were killed.
Studying the digestion of kiwifruit
Pigs were surgically fitted with an outside access to their intestine. Faeces were collected through anal stimulation, and samples were taken from the intestine for six-hour periods.
Testing feed supplements for their performance
Pigs were fed diets with different organic acids added. At a specific weight, they were slaughtered to collect samples.
Comparing the digestion of egg white in different forms
Pigs were acclimated to eating egg whites of different textures. After being deprived of water for two hours, they were fed again and then killed in intervals over six hours.
Testing ways of injecting nicotine
Pigs were anaesthetised and injected with nicotine through different methods. Blood samples were taken for two hours before the pigs were killed.
Measuring brain response to tail-docking
Piglets were bought at one to fifteen days old and anaesthetised. Their tails were cut off while measuring brain activity, and then they were killed.
Testing how cooking affects beef digestion
Pigs were fed ground beef for three days, either raw or cooked. They were then killed to cut out a part of their intestine.
Trialling a method to measure intestine fermentation
Young pigs were fed a test diet for two weeks while confined in metabolic chambers. After that, they were killed with an anaesthetic injected into the heart.
Testing how to gas piglets
Piglets were gassed plastic box to record their behaviour and vital signs.
Testing the accuracy of heart activity measurements
Pigs were anaesthetised, their open chests were equipped with electrodes and closed again. After measurements, the hearts were stopped, images were taken, and the hearts were removed.
Testing cholesterol absorption from baby formula
One-week-old piglets were kept in metabolic crates and fed baby formula for three weeks. They were then anaesthetised and killed to be dissected.
Studying the digestion of protein through serial slaughter
Ninety young pigs were housed individually for 13 days; their diet contained kiwi fruit and beef. All were killed to be dissected.
Studying the inner functions of the heart
Pigs were anaesthetised and their chests were cut open. Electrodes were inserted into their hearts so measurements could be taken before their hearts were removed.
Testing the effect of pain killers during tail docking
Piglets were anaesthetised and their tails were removed using different methods. During these procedures, the heart and brain activity of the pigs were measured.
Testing if pigs spread kauri tree sickness
A group of pigs was fed infected kauri roots for one day, and their faeces were collected for a week. Over 270 wild pigs were shot, and their stomach contents was sampled.
Trialing xenotransplantation for diabetes
Four pigs were used to harvest cells for transplantation into humans.
Studying sow and piglet behaviour in crates and pens
Sows and their newborn piglets were put in tightly confined crates or pens with slightly more room and their behaviour was observed.
Studying how ageing affects brain chemistry
Rats were kept in germ-free, individual cages before being killed. Their brains were used for tests.
Studying teen binge drinking
Young rats were force-fed alcohol repeatedly. Each time, blood samples were taken, and some were killed to take their brains after each alcohol day. The remaining rats were put through behavioural tests a few months later.
Teaching animal researchers
A range of animals is used to teach researchers handling and experimental methods.
Testing medications for drug addiction
Rats were taught to inject themselves with cocaine when they pressed a lever. Through many cycles of establishment and withdrawal, medications were tested for their effect on drug-seeking behaviour. Other rats were tested for their activity level on cocaine with or without medication. Some were put into water-filled cylinders to examine if medication influences how long they swim.
Testing effects of meth on brain protein
Rats were taught to inject themselves with meth or a saline solution when they pressed a lever. After 20 days, there were two weeks of abstinence. In the end, all were killed to dissect their brains.
Testing new drug formulations
Rats and rabbits were injected with a new anaesthetic, pinching their paw repeatedly to measure reflexes. Rats were giving the medication until they died.
Testing blood pressure drugs against seizures
Rats were implanted with devices to measure heart and brain activity through induced seizures without being anaesthetised. They were killed two days later, and their hearts were taken.
Studying the effect of prolactin on the brain
Virgin rats and rats who recently gave birth had a cannula (tube) placed in their brain and were injected with medication. They were injected with prolactin after two days and killed an hour later to dissect their brains.
Testing a surgical treatment for hypertension with diabetes
Transgenic rats were injected to develop diabetes. Their kidney nerves were surgically destroyed. They were restrained for measurements and sampling regularly. In the end, they were all killed.
Testing a new pain medication
Rats were operated on to cause pain build-up in their hind leg. After 10 days, they were injected with different variations of a drug or just a control solution. The effect was tested by poking their hurting leg and having them balance.
Trying to study depressants and antidepressants
Rats were kept isolated or in groups for nine weeks. They were injected with different drugs and put through behavioural tests (the notorious Forced Swim Test, among others). In the end, all were killed.
Studying how anaesthetics affect intestine movement
Guinea pigs and rats were anaesthetised, then dissected, and then killed, in that order.
Studying hormone sensitivity of the brain
Female rats were mated, gave birth and cared for their babies for three weeks. They had prolactin injected below the skull. They were killed, and their brains were removed.
Harvesting rabbit and rat hearts for lab tests
NZ White rabbits and rats were killed to use their hearts in lab tests.
Testing digestion of a pig food
Rats were fed a pig food and killed to examine their intestines.
Testing how heart calcium metabolism is different in species
Guinea pigs and rats were decapitated, and their hearts were quickly removed to study them.
Testing out cloning as a breeding tool
Cloned embryos were implanted into 17 mother sheep. Two sheep were killed when induction did not work. The lambs survived only minutes.
Undernourishing sheep to test glucose metabolism of their babies
Sheep were fed normally or only every three days. Some were killed during pregnancy. Born lambs were subjected to repeated glucose tolerance tests and killed.
Testing a medication for vocal chord injuries
Sheep were anaesthetised, tissue samples were taken from their vocal folds, and most were treated with different medications. All were killed after one month.
Testing if pre-term birth injections compromise glucose metabolism
Pre-term and full-term lambs were subjected to glucose tests, regular blood samples and a constant glucose infusion. Some were killed at four weeks, the rest at one-year-old.
Studying the effect of Huntington’s disease on ageing
Transgenic sheep were produced through breeding, and blood samples were taken.
Testing a first aide drug for severe bleeding
Sheep were anaesthetised and 30% of their blood was drained. After being treated with different medications, the drained blood was returned, and the sheep were killed.
Studying ear posture while in pain
Lambs had their tails docked with a tight rubber band without pain relief. Their pain behaviour was recorded.
Teaching animal researchers
A range of animals is used to teach researchers handling and experimental methods.
Training students in surgical procedures
Pigs and sheep were used for training future surgeons.
Teaching students surgical techniques
Sheep and pigs were used and killed in teaching students.
Studying effects of stunning before slaughter
Calves and sheep were anaesthetised. Some got 70-volt shocks to the shoulder. Others had a nerve exposed and stimulated before being stunned or cutting their throat.
Investigating intestine movements
Young pigs and NZ White rabbits were anaesthetised. A part of their intestine was pulled out far enough to record its movements and signalling.
Harvesting rabbit and pig eyes for lab tests
The eyes of slaughtered rabbits and pigs killed for experiments were used to analyse the structure of the cornea.
Causing sinusitis in rabbits as a model
NZ White rabbits were anaesthetised, and a sinus tract in their nose was blocked for four weeks to cause sinusitis. After another ten weeks with regular samples, they were killed.
Testing a new vaccine
NZ White rabbits were injected with a new vaccine type several times before being killed.
Harvesting eyes for lab tests
The eyes of pigs and rabbits killed for experiments were used to analyse the structure of the cornea.
Testing the toxicity of some substances
Young NZ White rabbits were force-fed different doses of toxic substances. Blood samples were taken before and immediately after killing them at set time points (or to end their suffering).
Using a new imaging technology
One NZ White rabbit and rats were killed, and their eyes were removed to use for the study.
Measuring contractions in exposed rabbit uteruses
Pregnant rabbits were anaesthetised, and their uterus was exposed. Measurements were taken while contraction-inducing injections were given. Then they were all killed for dissection.
Mapping wave patterns of the small intestine
NZ White rabbits were anaesthetised, their intestines were used for electrode mapping, and then they were killed.
Studying presence of a virus in rabbits
Wild rabbits were shot, caught by dogs or trapped to test them for virus strains. The infectious solution was then fed to NZ White rabbits in a lab to kill them later.
Harvesting rabbit colons for lab tests
NZ White rabbits were anaesthetised, a part of their intestine was cut out, and then they were killed.
Harvesting rabbit bladders for lab tests
NZ White rabbits were anaesthetised, their bladder was cut out, and then they were killed.
Testing an antimicrobial eye medication
NZ White rabbits were treated with Manuka honey solution in one eye and a control solution in the other eye for five days. Different values like tearing and irritation were measured.
Using muscles of dead rabbits for imaging
Two NZ White rabbits were killed to use for detailed muscle imaging.
Measuring jaw bone growth in young rabbits
Young rabbits were anaesthetised and had holes drilled into their jawbones to implant small pieces of metal. X-ray scans were made, and the rabbits were killed.
Testing the welfare impact of pindone toxin
Three groups of young NZ White Rabbits received pindone-toxin pellets on different schedules. Any rabbit still alive after three weeks was killed.
