Rats and mice are often the animals of choice to try and model human conditions, treatment and body functions - even though we know that the use of 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 quickly).
They also share many of our genes.1 But that's not surprising, even cats share many of our genes.2
Mice are also relatively easy targets for genetic manipulation, which is heavily used in cancer research.3 So it is not surprising, that over 95% of transgenic animals used in 2020 were mice (14,936 transgenic mice of 15,645 transgenic animals).4 Their small size also makes importing mice from other countries manageable.
Mice are mainly used for basic biological research, medical research, animal husbandry and testing in NZ. They are also used for veterinary research and the production of biological agents.
Mice in NZ have been used for:
- Drug research including safety and efficiency testing.
- For teaching purposes in schools, including observational activities and dissections.
- Disease research including research into the development of severe diseases (i.e., stroke, heart attack, cancer), modelling neurological disorders (i.e., Schizophrenia, Autism), modelling mood disorders (i.e., anxiety, and depression).
- Drug addiction research including research into the development and suppression of addictions and the impacts of drug use.
- Basic biological research into how parts of the brain work, damage affects the functions of the body, pregnancy changes body functions, wounds heal and how stress affects body and brain functions.
Places that use mice for science in NZ include crown research institutes, private companies and universities. Infact, most universities have their own breeding colonies. Otago University states on its website that they have a dedicated mouse testing room in the Behavioural Phenotyping Unit.5
Mice used for science in NZ are often sourced from breeding units at the respective institutions. Transgenic mice are sometimes imported from other countries like Australia, USA or Japan.
Discover real-life examples of how mice have been used in NZ below!
Testing a new papillomavirus vaccine
Adult colony cats were injected with a new vaccine or a control solution. Regular skin swabs and blood samples were taken.
Testing the effect of dietary fibre in cat food
Cats received three diets for three weeks each. Food intake was measured daily, and urine and faeces were collected for the last 5 days each time.
Determining how common E. coli is in pets
Rectal swaps were taken from cats and dogs presented at veterinary clinics, and their caregivers filled out a questionnaire.
Tracking and killing wild cats
Wild-caught cats were used to train sedation and collar fitting before being killed. Another group of cats was fitted with GPS collars for one year before being tracked down and shot.
Scoring the body condition of colony cats
The body condition score of 101 cats was determined, adding to routinely collected body weight data from the breeding colony.
Testing new toxin at Ngatapa Station
Toxic bait traps were placed on a property in Hawke’s Bay. Cat population changes were monitored with stationary cameras.
Testing a possum poison for other animals’ safety
Dogs, chickens and wild-caught cats were fed dead possum. Once they got used to eating this, they were fed possums killed with sodium nitrite, and signs for poisoning were monitored.
Testing nutritional value of new pet food
Cats and dogs were fed a test diet exclusively for several months. Some adults are kept in metabolic chambers for 10 days, and blood samples are taken at the end.
Testing new toxin at Toronui Station
Toxic bait traps were placed on a property in Hawke’s Bay. Cat population changes were monitored with stationary cameras.
Surveying caregivers on their cats’ personality
Cat caregivers in Australia and New Zealand filled in an online survey about their cats’ personality traits.
Training staff in wild cat handling
Wild cats are trapped and used to train staff in handling, sedation and collar fitting before they are killed.
Sampling cats’ saliva for feline autoimmune disease
Buccal swabs (inside the cheek) were collected from all cats in three British Shorthair breeding catteries.
Measuring vitamins in blood samples
Blood samples were taken from colony cats of different ages.
Collecting blood plasma for tests
Colony cats are switched from wet food to dry food for two days. Blood samples are taken before and after.
Testing a breathing mask on cats and dogs
Cats and dogs were held down tightly and fitted with face masks. Their breathing was measured for a while.
Testing pain medication with lasers
Colony cats were put into small chambers, and a laser was pointed at a shaved skin patch. The influence of medication on their reaction time was measured.
Investigating how worms spread between lambs and calves
Lambs and calves were treated against parasites and then infected with worm eggs. Infection status was monitored. This was repeated several times before all sheep were killed.
Testing a fertility treatment
Cows with fertility problems were treated with hormones for ten days or left untreated. All were then artificially inseminated.
Testing a supplement for more calcium intake
Pregnant cows were fed with or without a specific feed additive. After birth, all were fed the same diet. Blood samples were taken in the weeks around birth.
Checking endometritis rates in dairy herds
Some cows in several dairy herds were selected, and their vaginal discharge was measured and sampled. They were then impregnated as per standard agricultural practice.
Comparing weight gain with different diets
Newborn calves were raised on various milk, pasture, and pellets combinations. They were slaughtered at two years old, and their “quality” was measured.
Testing pain meds for disbudding
The horn buds of young calves who were slightly sedated were burned off with a hot iron. Half of them received pain meds beforehand, and blood samples were taken before and after. After 24 hours, the second group received pain meds, too.
Studying Ikeda infection and treatment
Regular blood samples were taken from cows on three different farms. Only some were treated against the parasite. Milk production and fertility were recorded.
Studying diarrhea infection
New mother cows had blood samples taken. If the sample was negative for a diarrhoea virus, they were sampled again after a while.
Studying genes for body size
Udders of dairy cows were slightly cut with a scalpel, and a tissue sample was taken with a biopsy needle.
Testing toxicity of a potential new fertiliser
Pigs were fed toxic bait and monitored until they died.
Studying stress around birth
Blood samples were taken from cows with a high or low risk of health concerns after birth.
Studying genetics of a missing tail
Cloned foetuses were implanted into female cattle to research taillessness. Some of them were killed during pregnancy to examine the foetuses. One tailless animal was killed at age 4, and one of the cloned calves died after birth.
Studying Ikeda (parasite) infection
Blood samples were taken from dairy cows and their calves directly after birth before separating them. After four months, the calves were sampled again.
Studying Osteoporosis in cows
Young female cattle who had given birth for the first time were sent to slaughter. Half of them had broken bones for between 2 and 10 days. Blood samples were taken before slaughter, and bones were collected after.
Testing a tuberculosis vaccine
Male calves were infected with bacteria. Two groups were vaccinated before or after the infection, and the third group was left untreated. All were killed and dissected 13 weeks later.
Testing feeding plans for better immunity after calving
Pregnant cows were fed either a bit too much or a bit too little. Blood samples were taken before, at, and after calving. Researchers also took liver samples with a 20-cm biopsy needle and vaginal samples with a small brush and a scoop at these dates, except for the date of birth.
Testing if blackcurrant extract is toxic for dogs
Dogs are given blackcurrant pills for several days. The number of pills increases over time up to 60 tablets. Their health is monitored.
Practising first aid on working dogs
The 2-day course involved training students with mannequins, placing an IV catheter in the handler's dogs (dogs were lightly sedated), a live demo and practical exercises on anaesthetised sheep that would killed afterwards.
Testing intermittent fasting
Dogs will be fed three different ways for one week each. A high carb diet twice a day, a high carb diet every two days, and a high fat, low carb diet every two days. Each dog will have 12 blood samples taken throughout the study.
Testing the fitness level of police dogs
Police dogs are fitted with a catheter for a whole week and get infused with a marker solution. They are fitted with an activity measuring collar and regularly have blood sampled.
Testing how sensitive some dog breeds are to pain
Dogs were tested for their pain threshold by having a disk the size of a coin placed onto one of their forelegs. This disc could be heated up remotely. Several tests with 10-minute breaks in-between were performed, where the disk temperature was raised until the dog showed signs of pain. Almost half the dogs showed burn marks after testing.
Testing what dogs prefer to eat
Dogs are fed three different diets (either high fat, high carb, or high protein) over 28 days once a day. The dogs are offered each of the three diets at once and in high quantities. Regular stool samples are taken. Blood samples are taken from dogs that have been fasted (18 hours with no food).
Studying how long morphine affects dogs
Dogs scheduled to have ovaries and uterus removed at a teaching clinic are used. Premedication, including morphine, is given 45min before the surgery. Dogs are fasted for 12 hours and water is withheld for about 1 hour before surgery. Blood samples are taken regularly for 4 hours.
Studying the influence of diet on working farm dogs
Dogs working on farms are fed either a premium diet or a standard "home-kill plus tux" diet. All dogs have a collar to measure activity. Body weight, condition, and blood samples are recorded regularly for a year.
Testing a new biomarker
For regular blood samples over nine weeks, dogs are fasted overnight at the lab and returned to their owners the next day until the following sampling.
Studying if farm dogs are overworked
A glucose sensor is stuck between the dog's shoulder blades and sutured in place before a bandage is stapled over it. After being fasted, each dog is studied on glucose levels and activity for two days.
Testing different methods for skin sampling
Samples from the skin of dogs are taken in different ways: plucking hair with the roots, sellotape strips pressed down and ripped off several times, acetone-soaked cotton buds and solvent washes.
Testing nausea in dogs with different anaesthesia
Dogs who are about to have surgery are given different combinations of anti-nausea drugs to test the effects.
Testing a breathing mask on cats and dogs
Cats and dogs were held down tightly and fitted with face masks. Their breathing was measured for a while.
Learning when anaesthesia is lethal
The anaesthesia of pound dogs was gradually increased to dangerous levels. Students also practised taking blood samples, placing catheters and giving blood transfusions to the dogs, all while a teacher supervised.
Testing a gene therapy for Mucopolysaccharidosis
Newborn puppies are genotyped and divided into treatment groups. Some are left untreated. Some are injected with potential medication. The injection is into the neck vein or into the liver vein. For that, puppies are anaesthetised, have their belly cut open and the drug injected into the liver vein. All puppies are killed after regular blood and one spinal fluid sample.
Refining treatment for a (human) genetic disorder
Puppies with the genetic disorder MPS IIIA were treated with enzymes injected directly into the spinal fluid near the brain. Treatment was done until 22 -24 weeks old and varied in dose and frequency. In the end, the puppies were killed for dissection.
Studying fish behaviour in groups of multiple species
Mixed-species groups of fish (partly caught in the wild) were placed in a tank and fasted for 24 hours. Food was given and an artificial predator was used to study behaviour.
Studying food chains near CO2 vents
Fish and snails were observed and counted near CO2 vents and at control sites. Fish were also caught to examine their stomach content.
Studying fish behaviour in single-species groups
Young fish were caught in the wild and split into groups of 15, 75, and 150 animals. After being fasted for 24 hours, food was given and an artificial predator was used to study behaviour.
Testing the side-bias of fish (if they prefer to swim left or right)
Wild-caught fish were kept for 1.5 years before each fish was placed on a runway to observe their behaviour. Afterwards, fish were observed for schooling movements and some were killed to dissect their brains.
Studying effects of Climate Change on farming in damselfish
Fish were observed for their algae farming behaviour near CO2 vents and at control sites (Bay of Plenty). Small areas were covered to keep the fish away for a month and compare algae growths measured to compare.
Trying to estimate habitat quality from body condition
Snappers were hatched from eggs and raised on commercial food. They were kept in 800-litre flow-through tanks containing 170 to 260 fish each. At 80 days, they were fasted killed.
Trying different techniques for tagging fish
Fish were bait-trapped and treated for parasites. They were used to test different tagging methods. In the second part of the experiment, fish were caught with two different methods, after which injuries and survival over 12 days were monitored.
Studying fish near volcanic vents to learn about Climate Change
Fish near volcanic CO2 vents and at control sites were observed and counted. The reaction to baited underwater cameras and predator threats was filmed. Aquarium experiments were conducted with caught fish of different species.
Verifying “fish-friendly” flood pumps
Eels were caught, measured and tagged with transponders into the gut skin. They were later re-captured, observed for wounds and fungus and killed to examine internal damage.
Testing the temperature tolerance of Antarctic fish
Wild-caught fish were kept individually for months in tanks. During temperature experiments, fish of each group were tested for their breathing ability in small tubes before all fish were killed.
Slowly poisoning fish
Snappers were fasted for three days and then fed with toxic fish. Several died during feeding, and the rest were killed at the end.
Studying population changes in reef fish
Over 1,000 fish were caught by spearing at three NZ locations.
Testing the hearing of fish
Fish were anaesthetised and strapped to a plastic slide near an underwater speaker. Electrodes were placed in their head and gills to measure brain activity. For medical imaging, fish were restrained in a plastic tube with a sponge to keep them wet.
Developing a model for thermal stress in humans
Guinea pig pups were lightly anaesthetised, connected to devices measuring heart activity and breathing, and wrapped in a temperature-controlling blanket. Their body temperature was either forcefully raised or dropped.
Testing how too much fructose is bad during pregnancy
Female guinea pigs were mated; some were fed additional sugary water until birth. The pups were used for several glucose tolerance tests and X-rays. All pups were killed in the end.
Testing a seizure medicine for preterm babies
Pregnant guinea pigs were induced to give birth early, to test medication on their pups.
Testing the effects of sedatives
Young guinea pigs were treated with different sedatives. Their heart rate and blood pressure were measured before and during each treatment.
Testing an refined way of anaesthesia in guinea pigs
Guinea pigs were made to inhale anaesthetic gases. Different probes were inserted and attached to the animals to measure responses.
Studying the effect of fructose during pregnancy
Guinea pigs were fed either normally or supplemented with fruit sugar before and during pregnancy until birth. Mothers and pups were tested for glucose tolerance.
Studying the effects of meth
Guinea pigs were injected with sedatives, caffeine, and later meth. Under anaesthesia, their livers were cut out before they were killed.
Studying preterm birth effects on the brain
Pregnant guinea pigs were grouped to give birth normally or be induced early. The pups were put through behavioural tests and then killed for dissection.
Studying trauma and treatment of cochlear implants
After destroying their hearing with noise, guinea pigs were fitted with cochlear implants. Treatment success was tested before they were killed.
Testing the measurement of pupil reflexes in Alzheimer’s research
Guinea pigs were repeatedly flashed in the eyes with a phone light to record the pupil responses.
Teaching animal researchers
A range of animals is used to teach researchers handling and experimental methods.
Investigating mechanisms slowing down the heart rate
Young guinea pigs were injected with blood thinner before being anaesthetised and dissected.
Testing a device to assess hearing
Young guinea pigs were anaesthetised, electrodes placed under their skin, and their brain's response to sound was measured. All guinea pigs had one ear damaged, some both ears, before all were killed.
Studying changes in the inner ear due to inflammation
Guinea pigs were injected into the ear with bacteria. Medical scans were done after injecting chemicals, and most were killed for dissection.
Studying the effects of medication on memory
Guinea pigs were force-fed different drugs and later tested in a water maze before some were killed. Another group was exposed to carbon dioxide and decapitated.
Studying how anaesthetics affect intestine movement
Guinea pigs and rats were anaesthetised, then dissected, and then killed, in that order.
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.
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.
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.
