Fish were the single most used species for science in 2020.1 Most were used in basic biological research (the study of living things and their processes) and were also used in animal husbandry research, species conservation, and more.
Why so many fish are used: Most fish have a very short reproductive cycle, meaning they can be bred quickly, they also don't generally cost much to breed or house, making them desirable test subjects in science.
Zebrafish are regularly used as animal models for human development. A single pair of zebrafish can produce 100 to 300 embryos in one week. Zebrafish embryos are transparent and have their whole “body plan” laid down only 2 days after fertilisation. The similarity between human and zebrafish genomes is often cited as a reason to use them in models.2
Snapper3, eels4 and other fish that are eaten5 are also regularly used in science because of their importance to the commercial fishery. This industry will always be looking for ways to maximise its profits.4
Many fish living in the wild are studied as a way to research climate change.
Fish in NZ have been used for:
1. Research into optimising the growth and use of fish for human consumption. This includes research into optimal feeding, genes responsible for body size and growth speed.
Other examples include:
- Testing environmental influences and impacts (i.e. how salmon farms affect surrounding ecosystems).
- Researching how toxins accumulate in fish organs (i.e. algae toxins, mercury).
- Finding treatments/vaccines for illnesses and injuries from aquaculture.
- Manipulating the life cycle of fish to try and maximise reproduction.
2. Teaching purposes in schools and universities, including observational activities and dissections.
3. Medical research (i.e., they are used to try and model humans).
Examples include:
- Fish larvae have been used to try and model human immunity.
- Fish embryos have been used to try and study human foetal development.
- Genetically modified fish have been used to try and study adipostasis and glucose metabolism.
4. Basic research into fish biology, including research into how sharks sleep, how hearing develops in fish, microbes inside fish stomachs and the spread of viruses in wild fish.
5. Research into the effects of climate change, including research into marine food webs, biodiversity changes, species behaviour and interactions and predator abundance.
Other examples include research into:
- Measuring the genetic reactions to stress.
- The effects of herbicides on fish behaviour
- How well Arctic fish do at higher temperatures.
6. Species conservation, including research into killing unwanted species (i.e., koi carb, catfish, rudd, and goldfish).
Other examples include research into:
- The efficiency of one-way barriers on lake outflow.
- Fish-friendly flood pumps (i.e. for eels).
- Finding out where wild fish breed the most (to see which areas are worth protecting).
- Optimising catching/tagging methods for re-capture projects.
7. Ecotoxicity testing (i.e., in tests that measure how biological, chemical or physical stressors affect ecosystems).
Places that use fish for science in NZ include universities, crown research institutes, polytechnics, commercial organisations and others.
The University of Otago for example has its own Zebrafish Facility. The MPI naturally has a research interest in fisheries and ecosystems. As a crown research institute, NIWA’s research in the fields of aquaculture, fisheries, and the Antarctic is funded by the government. Cawthron Aquaculture Park is home to a dedicated Finfish Research Centre (FRC), which opened in 2018 with funding support from the Ministry of Business, Innovation and Employment (MBIE).
Fish used for science in NZ are sourced from breeding units, fish farms, commercial sources, and public sources, are born during projects or are captured in the wild.
Discover real-life examples of how fish have been used in NZ below!
Measuring thickness of blood vessel walls
Colony cats were anaesthetised, and the blood vessels under their tongue were measured with a special hand-held camera.
Collecting faeces for lab tests
Colony cats were fed different diets for three weeks before their faeces was collected for analyses.
Surveying caregivers on their cat feeding
New Zealand cat caregivers filled in an online survey about their household demographics and what/how they feed their cats.
Testing new toxin in Hawke’s Bay (again)
Toxic bait traps were placed on a property in Hawke’s Bay. Cat population changes were monitored with stationary cameras.
Assessing stress reaction to anaesthesia in cats
Cats were put through several anaesthetic infusions with six-day breaks in between. Regular saliva samples were taken 24 hours before and after, and urine was collected through a wire mesh tray.
Trialling ready-made toxic bait
Toxic bait stations are set up in a regular pattern in an area and left for two weeks. Trial cameras and tracking tunnels monitor the effect on the population.
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.
Testing if a human diabetes drug might also work in cats
Research cats were placed in individual cages four times (one week each time) and injected with either a diabetes drug or a control solution. Several blood and urine samples were taken.
Testing a cat food supplement for tooth health
Colony cats were anaesthetised, and all plaque was removed from their teeth. Four weeks later, new plaque build-up was measured.
Sampling cats for feline immunodeficiency virus (FIV)
Buccal swabs (inside the cheek) were collected from almost 200 cats at 15 veterinary clinics.
Testing food preferences of cats
Cats were fasted for two hours in the mornings and then presented with different foods (lamb and beef parts) to measure their consumption.
Monitoring wild cats for a year
Wild cats are trapped and fitted with GPS collars. After one year, they are recaptured and killed.
Trialling a lighter rifle to kill trapped wild cats
Captured wild cats were shot in the head using an air rifle and were assessed to confirm death by recording the time to loss of heartbeat.
Testing a predictive marker for cancer survival in cats
Veterinary samples of cats with this form of cancer were analysed and compared with their remaining survival since diagnosis.
Monitoring outdoor cat behaviour
Privately owned cats with outdoor access were fitted with camera and GPS collars for up to three days.
Testing a diagnostic for feline coronavirus
Cats with specific symptoms were used to take blood, tissue, and fluid samples. Some blood samples were taken from control cats.
Investigating how worms spread between lambs and calves
Lambs and calves were infected with worm eggs to see if parasites from cattle can infect sheep.
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
Pregnant cows were fed a toxic ingredient to see if it is toxic.
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.
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.
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 a 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.
Testing a UV treatment for bacterial eye infection
Pigs’ eyes were acquired for testing a new treatment, followed by tests on live mice, most of whom were killed.
Studying methane emission and meat quality
Lambs were tested and killed to assess the relationship between methane emissions, carcass weight and meat quality. Almost 2,000 were put through emission measurements. Over 17,000 were slaughtered.
Testing if anaesthesia affects the sleep–wake cycle
Mice were kept on a 12-hour light/dark cycle and then switched to total darkness. They were anaesthetised twice to see the effect on their activity cycles, and all were killed in the end.
Testing the influences on growth
Transgenic and "normal" mice were kept in small groups and killed at different ages. Fat and muscle tissue were dissected, and the hearts were taken.
Testing a new way to kill lab mice
Mice were fed cream cheese containing different amounts of a sedative. Behaviour was recorded during the sedation period and while gassing them with CO2.
Testing a possible cause for cataracts
Transgenic and "normal" mice were used to study the development of cataracts. They were anaesthetised, images of their eyes were taken, and then they were (likely all) killed.
Studying chronic stress
Mice were handled daily, had vaginal smears, and some were subject to the notorious Forced Swim Test. Half of them were additionally stressed daily in various ways to see the difference it makes.
Trialling cancer drugs in mice after similar drug failed in humans
Mice were force-fed daily with two new drugs in different dosages. Others were force-fed a control solution, and some were left untreated. In the end, the animals were killed with CO2 and dissected.
Testing if exercise influences treatment success with cancer
Mice were injected with cancer cells. When tumours reached an “ethical” limit, they were injected with a labelling agent, anaesthetised and killed to be dissected. This was repeated, while some mice received cancer treatment.
Testing if exercise influences muscle mass with cancer
Mice were injected with cancer cells, and some received immunotherapy once the tumour reached a specific size. When tumours reached an “ethical” limit, they were killed. Cancer-free control mice were killed simultaneously.
Studying the interaction of hormones and stress
Transgenic mice had their brains injected, some had their ovaries removed, and some were restrained for repeated blood samples. In the end, all mice were killed.
Studying movement processing in the brain
Transgenic mice were put through behavioural tests while half of them had a part of their brain-damaged. Some mice had a window put into their skull to take recordings of their brains while awake. They had limited access to water and were forced into a device that stopped them from moving their head. In the end, all were killed.
Testing seizure activity in transgenic mice
Mice with specific genetic limitations were bred. Some were killed for dissection, and others were injected with a gene activation drug before they were killed.
Testing a seizure treatment
Genetically modified mice had wires and a cannula implanted in their brains, and were injected to cause seizures. The next day, their genetic mutation was activated. The test was repeated before they were all killed.
Observing cancer growth with/without treatment
Mice were injected with human breast cancer cells. The growth was monitored and sampled (biopsy). Some were operated on to remove their ovaries and some were treated with drugs before all were killed.
Testing how hormones influence activity while pregnant
Transgenic and “normal” mice were used to test the influence of pregnancy and hormones on activity and anxiety. They were kept in single cages with running wheels and subjected to behavioural tests. The transgenic mice were killed in the end.
Harvesting colon tissue for laboratory tests
Pigs were killed and their colon tissue was used for laboratory testing.
Testing if pigs can be fed by-products from biofuel and food processing
Pigs were fed a standard diet or a diet containing by-products from other industries. They were slaughtered to compare meat growth and quality.
Studying starch digestion in pigs to try and model humans
Pigs were fed different diets containing durum wheat or rice. Some had regular blood samples taken through a catheter. All the animals were killed at the end.
Validating a treatment for stomach muscle dysfunctions
Pigs were anaesthetised, their bellies were opened, and electrodes were placed on their stomach walls before and after damaging some stomach tissue with heat. All pigs were killed.
Assessing pigs as digestion models for humans
Titanium tubes were implanted into pigs’ intestines. Digested food was collected through the tube for 9 hours.
Testing the effect of different species’ milk on brain gene expression
Piglets were fed different kinds of milk from other species for 15 days. They were killed to dissect their brains.
Testing transmitter implantation on wild pigs
Wild pigs were captured, and three different tracking devices were fixed to or implanted into each one. After 104 days, they were tracked down and killed.
Investigating oxygen content in the gut
Pigs were fed diets with different or no protein sources as a control. After a week, all were killed.
Testing a UV treatment for bacterial eye infection
Pigs’ eyes were acquired for testing a new treatment, followed by tests on live mice, most of whom were killed.
Testing the effect of different species’ milk on protein digestion
Piglets were fed different kinds of milk from other species for 15 days. They were killed to dissect their stomachs.
Testing the strain on a temporary surgical implant
A surgical implant was screwed to a severed pig head, and measurements were taken via laser scanning.
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.
Harvesting eyes for lab tests
The eyes of pigs and rabbits killed for experiments were used to analyse the structure of the cornea.
Testing a treatment for stomach muscle dysfunctions
Pigs were anaesthetised, their bellies were opened, and electrodes were placed on their stomach walls before and after damaging some stomach tissue with heat. All pigs were killed.
Testing how electric stimulation affects stomach movements
Nine pigs were anaesthetised, their bellies were opened, and electrodes were placed on the stomach walls. Electric stimulation tests were performed before the pigs were killed.
Studying food intake in an autism "model"
Pregnant rats were injected to cause autism-like symptoms in their babies. The male babies were put through behavioural tests with control animals as well as a feeding study. Some were fasted for 16 hours and killed by flushing their hearts.
Testing the safety of a probiotic supplement
Rats were force-fed with a probiotic solution or control solution. After two weeks, they were killed for dissection.
Studying the effects of obesity and mussel powder on bone health
Rats were kept alone and fed different diets containing normal or high amounts of fat or sugar. Some were supplemented with Greenshell mussel powder. X-rays were done, and some rats' ovaries were removed. Ultimately, all were killed by bleeding them out.
Testing if a brain region controls memory
Some rats had their brains surgically heat-damaged. Electrodes were implanted to monitor brain activity and to stimulate the damaged parts with light. Rats then had to re-perform memory tests to see the impact before all were killed.
Studying the communication between inner ear and brain
Rats were anaesthetised, and their inner ear was partly removed, before parts of their brains were stimulated with wire electrodes. Reactions of the rat's eyes and brain were recorded. In the end, all rats were killed.
Testing a connection between tinnitus and brain function
Rats were anaesthetised and one ear was damaged with noise. Rats were taught that silence meant they would get electric shocks and freeze in fear. This was a test for tinnitus.
Testing diabetic rats’ hearts
Genetically diabetic fat rats and their lean littermates were anaesthetised. Ultrasound images were made from their hearts. All were killed and dissected.
Testing the effect of diabetes on pregnancy hormones
Rats were anaesthetised, and their brain was accessed through the mouth to measure reactions to stimulation. In the end, all rats were killed.
Trying to study schizophrenia
Half of a group of pregnant rats were injected to affect their babies' brain development. Some pups were allowed to grow up to test their behaviour.
Releasing a rat family into the wild to see where they go
A wild-caught rat was mated, fed a fluorescent dye, and released again with her pups. Traps, tunnels, and cameras were set up to track and eventually recapture the animals, which did not work 100%.
Comparing digestion of sheep versus cow milk yoghurt
Rats were fed cow milk, sheep milk, cow yoghurt or sheep yoghurt for two weeks. They were gassed with CO2 before their necks were broken.
Testing a rat poison that is unattractive for dogs
Rats were kept in small cages and fasted overnight. Then, they were given two food trays. One of them was scented with lion, tiger, or dog faeces.
Comparing digestion of sheep versus cow milk
Rats were fed a test diet containing beef protein and received cow milk or sheep milk instead of drinking water. After 28 days, all were killed.
Testing medication after heart attack
Rats were anaesthetised, and their hearts were exposed. A heart attack was simulated by blocking an artery. Some had dye injected into their brains, and some were injected with test drugs. All animals were killed.
Testing a medicine against drug addiction
Mice's tails were dunked in hot water. Rats were put through cycles of drug-seeking and withdrawal using self-injection of cocaine. Other rats were injected, and their behaviour was tested (with the notorious Forces Swim Test, among others).
Studying cell death in breast tissue
Mother rats had some of their newborns taken away, and several of her teats were sealed off after two weeks. They were killed after different waiting times to analyse the dying tissue.
Investigating how worms spread between lambs and calves
Lambs and calves were infected with worm eggs to see if parasites from cattle can infect sheep.
Using sheep to try and model how well humans will heal after dental surgery
Sheep had healthy teeth pulled out and the sockets treated in different ways to compare how well the body will heal after a tooth is removed when left untreated vs using a bone graft.
Preclinical testing of a gene therapy for Batten disease
Sheep with and without a specific gene mutation were checked and scanned regularly for nine months. Affected sheep received gene therapy at different ages. Treated sheep were killed.
Testing if blocking a cell signal can prevent foetal brain injury
Pregnant sheep were anaesthetised, and the foetuses fitted with electrodes. The umbilical cord was blocked for most of them, and half were treated with a test drug. Mothers and unborn lambs were killed three weeks later.
Testing the combination of drugs for congestive heart failure treatment
Sheep were anaesthetised and subjected to surgery. Electrodes were used to pace their hearts faster while testing the effect of different drugs.
Testing the best way to deliver gene therapy drugs
Sheep were anaesthetised. Their heads were drilled into, and their brains injected with test drugs. They were killed after three weeks.
Testing the potency of pneumonia vaccines for sheep
Lambs were vaccinated twice and regular blood samples were taken for 34 weeks, to test different pneumonia vaccines for sheep.
Testing the effects and wash-out of painkillers
Lambs were treated with different painkillers or no painkillers at all before tail docking and castration. Their behaviour was monitored.
Developing “hyperimmune” milk
Sheep were injected with Covid-19 vaccines to see if they produced milk that could be marketed to consumers as providing immunity against certain diseases.
Studying the genetics of Batten disease on chimeric lambs
Sheep foetuses were removed. After swapping cells between them, they were inserted into other ewes. Lambs born were subjected to X-rays and, at one to three years old, were bled out for dissection.
Testing pacemaker adjustments
After causing them heart failure, sheep were surgically fitted with pacemakers and measurement devices. Those who survived the procedures were killed after six months.
Studying methane emission and meat quality
Lambs were tested and killed to assess the relationship between methane emissions, carcass weight and meat quality. Almost 2,000 were put through emission measurements. Over 17,000 were slaughtered.
Studying the effect of chemicals in normal and high blood pressure
Sheep were surgically fitted with a clip around an artery and compared with others without clips. Measuring devices were added before injecting different chemicals into the hearts of the conscious sheep.
Comparing success of muscle repair surgery with or without weeks of delay
Sheep were anaesthetised and one side of a pelvis muscle was detached. After several weeks, the muscle was repaired. How well the sheep then walked was noted before all were killed.
Comparing different designs of dental implants
Sheep were anaesthetised. One leg bone was exposed and fitted with several implants. After 12 weeks, all were killed.
Trying to model human brain injuries
To study changes in different areas of the brain after brain injuries. Sheep were used to study the effects of traumatic brain injuries in humans.
Questioning vets on pain management
Veterinarians completed a questionnaire regarding pain and pain management in rabbits and guinea pigs.
Testing immunity assays for RHD virus
Wild-caught rabbits were injected with Rabbit haemorrhagic disease (RHD). All that did not die were killed.
Testing treatments for another medication overdose
NZ White rabbits were anaesthetised, and catheters were placed in blood vessels and intestines. After poisoning them with an overdose of medication, different treatments were tested for one hour.
Testing treatments for anaesthesia overdose
NZ White rabbits were restrained, fitted with catheters and needle electrodes and then given an anaesthetic. Saline or lipid solutions were given, and the reaction was monitored.
Testing retention time of eye medication
NZ White rabbits were restrained, and medication was put into their eyes. The reaction was recorded.
Harvesting rabbit and rat hearts for lab tests
NZ White rabbits and rats were killed to use their hearts in lab tests.
Testing a treatment for medication overdose
Rabbits were anaesthetised, and devices measuring blood pressure and heart rate were placed. After testing a toxicity treatment, all were killed.
Testing different treatments for medication overdose
NZ White rabbits were anaesthetised, and devices to measure their circulation were placed. Their hearts were stopped, and “first aid” was performed before all were killed.
Testing a treatment combination for medication overdose
NZ White rabbits were anaesthetised devices to measure their circulation were placed. Their hearts were stopped, and “first aid” was performed before all were killed.
Studying rabbit eyes to learn about human glaucoma
Dutch black-belted rabbits were anaesthetised and killed. Their eyes were removed and studied.
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.
