IN SCIENCE
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Benefits of Animal-Based Science
The benefits or successes of animal-based
science are so widespread that it is hard to imagine any area of our
lives that is unaffected by them. The specific benefits of animal-based
science are therefore far too numerous to list here, so the general
benefits will be outlined first, then just a few specific
benefits will be listed as examples, and that will be followed
by a very brief history showing when
some important biomedical developments occurred.
Click on the following headings to find out more. Even more information
can be obtained within each section by clicking on highlighted words.
General Benefits of Animal-Based
Science
Higher order
animals are used in research, teaching
and testing because of the benefits
they bring to both animals and people. Those benefits are the reasons
why a research, teaching or testing procedure is done in the first place
(i.e. the aims of the work).
Research using animals
has various broad aims (see Why Study
Animals?, which include:
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Improving the health,
welfare and
productivity
of farm animals and other production animals
Finding better ways to preserve, protect and manage
a range of animal species (especially endangered and native
animals) to maintain a balance that is ecologically
stable and well adapted to the New Zealand environment.
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Developing more humane and effective pest
control methods to protect endangered animals and plants from
the species that threatens them and to prevent damage to the environment.
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Broadening the foundations of biological science, including
our knowledge and understanding of life processes in all animal species.
Teaching.
The knowledge we gain about animals and people through research
needs to be passed on, now and in the future, to those who are or who
will become:
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Doctors, nurses and other human health professionals.
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Animal care personnel, veterinarians, farmers, conservation
managers, zoo keepers and others engaged in animal-related activities.
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School, polytechnic and university teachers; researchers
in animal-based science.
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Anyone interested in how their own body works or in
what the welfare needs of animals are, and those interested in the
coexistence of animals and people.
All such education involves describing, explaining and
demonstrating how the bodies of animals and people work and how the functions
of the body can be modified to benefit animals or people. Teachers are
required to apply the Three Rs Principle whenever they consider using
animals during a teaching exercise.
Testing
is done as a check on the safety of new drugs or substances for human
or animal use, and to check whether new batches of drugs and other agents
like vaccines work. There is a legal requirement to test how safe and
effective chemicals, drugs and other therapeutic agents are before they
can be sold. Well-known tests that cause suffering when the test substance
is poisonous, corrosive or otherwise harmful are the LD50
Test and the Draize
Eye Irritancy Test. All three of the
Three Rs have been successfully applied to testing and
scientists are working hard to find more and better ways of applying them.
For instance, replacement
of animals with tissue cultures (cells kept alive in a test tube)
is now used extensively, especially in the early stages of testing when
whole animals were once used. Also, employing careful statistical analysis
and substitutes for animals (replacements) have markedly reduced
the number of animals required in testing procedures, and using earlier
more humane endpoints thereby ending a noxious testing procedure much
sooner than used to be the case is a form of refinement.
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Some Specific Benefits of Animal-Based
Science
Some of the examples of the benefits provided here arose from direct
observation of people. However, the details of the body mechanisms in
people were mostly worked out by studying similar functions in animals.
The benefits brought to animals were mostly worked out by direct animal
studies, but sometimes arose from studies of people.
Anaesthetics
General anaesthetics, which are the chemicals used to make you unconscious
during an operation, were first discovered and used in the mid 1800s.
Before that, what passed for surgery was little more than refined butchery.
Surgical operations - like amputations, removal of bladder stones, caesarean
sections and others were done with the conscious patient strapped
to the operating table. Speed during the operation was of utmost importance
to reduce the period of agony and terror. Controlling blood loss was
attempted by cautery using hot irons or boiling oil or tar. Imagine
if you can the screams as flesh and bone were cut with scalpel and saw,
and imagine the sizzle and stench of burning as the stumps of amputated
limbs were plunged into boiling oil.
The ability to safely cause unconsciousness, and maintain it, using
the first general anaesthetics was a key event which began the transformation
of surgery from the bloody race against the clock it used to be into
the refined, sophisticated and successful activity it usually is today.
The later discovery, development and assessment of a range of other
general anaesthetics which are safer both for the patient (they do not
explode and are less irritating to body tissues) and the surgeon (they
are non-explosive and less addictive) also contributed to this process.
These developments have brought huge benefits to both animals and people.
The understanding of how anaesthetics work, the discovery and testing
of new and better anaesthetics and the continuing refinement of the
methods of giving anaesthetics to make them safer have all relied heavily
on animal-based studies.
Antiseptics, Asepsis
and Antibiotics
Today we take it for granted that bacteria, viruses and other micro-organisms
cause infections. As a result we understand the value of using antiseptics
to make things sterile and cleanse wounds, and we know how important
it is to do surgical operations using aseptic
techniques to prevent micro-organisms from being introduced
into the body during the operation. Also, we can use antibiotics
to kill bacteria which might enter the body during the operation or
which might infect the wounds after it.
It was not until the mid to late 1800s that the link between micro-organisms
and infectious diseases was both established and accepted. Before that,
signs of infections in wounds were thought to indicate that the healing
process had started. Thus, pus was known as laudable pus,
and surgeons and physicians with accumulated pus on their clothing used
to pass infections from patient to patient. At that time, if the trauma
of surgery without anaesthetic did not kill you then infection of the
wounds caused by the surgery probably would. Moreover, the hazards of
childbirth were greatly increased by the common but unknowing introduction
by midwives and physicians of micro-organisms into the female genital
tract. That regularly caused fatal infections which revealed themselves
as the then common condition of childbed fever, a condition
which is virtually unknown today. Also common at that time were other
infectious conditions including blood poisoning, pneumonia, dysentery,
infections of the urinary and genital tracts, and skin rashes, sores
and ulcers.
The incidence of these and numerous other infectious conditions in animals
and people has been reduced dramatically by the discovery, refinement
and assessment of antiseptics, aseptic techniques and antimicrobial
substances (including antibiotics) which can be used externally or taken
internally. Improving our knowledge in this area has depended heavily
on animal-based studies.
Vaccines
People and animals can be infected with dangerous micro-organisms that
cause pain, distress, suffering, lasting harm and/or death. Animal-based
scientists demonstrated how micro-organisms cause disease and how
body defences fight those disease agents. This in turn led to the development
of many vaccines which improve body defenses, so that the body can rapidly
kill off very strong and nasty disease agents before they do much damage.
At least 21 vaccines
now protect people, and at least 56 vaccines now protect
animals of different species (cats 4, dogs 6, horses 5, cattle 12,
sheep 14, pigs 7, poultry 7). Vaccines therefore make major contributions
to preventing suffering in people and animals. As new infectious diseases
appear (e.g. HIV-AIDS in people and a similar disease in cats, and equine
morbillivirus which can infect both horses and people) new vaccines
will need to be developed to provide protection against them.
The enormous reduction in pain, suffering, sickness, disability and
death which has been achieved by the contributions of biomedical and
veterinary sciences to the control and in some cases the elimination
of infectious diseases through vaccination is an extraordinary achievement.
It is just one of many such contributions to animal and human health
and well-being.
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A Very Brief History of Biomedical Developments
Direct animal studies led to many of the biomedical developments
listed here, especially those made during the last 100 years. However,
some of these developments first arose from direct observation of people.
In those cases the details of the body mechanisms in people were mostly
worked out by studying similar functions in animals. Parallel developments
benefited both people and animals.
1500s
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Ligatures used for the first time to stop bleeding
in wounds (Ambroise Pare).
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An ointment rather than boiling oil recommended for
treating wounds (Ambroise Pare).
1600s
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The first serious study of body metabolism published
(Santorio Santorio).
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Circulation of the blood first described (William Harvey).
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How the lungs work first described.
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First description of bacteria and of blood cells (Antonie
van Leeuwenhoek).
1700s
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Blood pressure measured for the first time.
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First demonstration of a cure for scurvy using fruit
(James Lind) vitamin C, the important substance in fruit was
not discovered for another 200 years.
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First successful vaccination in England, thus laying
the foundations for modern immunology (Edward Jenner).
1800s
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Stethoscope invented (Rene Laennec).
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First major surgical operation carried out using ether
as a general anaesthetic (Crawford Long, USA).
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Modern surgery revolutionised by employing aseptic
techniques (Joseph Lister).
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The discovery of X-rays (Wilhelm Roentgen), leading
eventually to their use in diagnosis of internal disorders like broken
bones and the presence of cancer.
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Discovery of Radium (Pierre and Marie Curie), which
eventually led to its use to treat cancer.
1900-1920
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Discovery of the first four major blood groups: A,
B, AB and O (Karl Landsteiner).
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Discovery of antibodies.
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Understanding hormone systems and how they work.
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Ability to do corneal transplants.
1920-1950
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Insulin isolated and used to successfully treat diabetes
(Frederick Banting and Charles Best).
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The antibiotic penicillin discovered (Alexander Fleming).
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Discovery of vitamins.
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Blood groups M and N discovered.
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Blood transfusions used.
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New effective antibacterial treatment against streptococci
using a substance called Prontosil red (Gerhard Domagk).
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Discovery of how nerves work.
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Diphtheria vaccine developed.
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Improved anaesthetics developed for surgery.
1950-1970
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Understanding the mechanism of hearing.
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Understanding how muscles are controlled.
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Development of heart-lung machine, open heart surgery,
heart pacemakers and heart valve replacements.
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Kidney transplants from close relatives began.
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Poliomyelitis vaccine developed.
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Drugs to treat high blood pressure developed.
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Drugs to treat certain types of mental illness developed.
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New materials and surgical techniques for joint replacements
developed.
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DNA molecular structure determined (James Watson and
Francis Crick), laying the foundations for modern genetics and cellular
control of body functions.
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First contraceptive pill, Enovid 10, made available
commercially.
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German measles (rubella) vaccine developed.
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Coronary bypass operations began.
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Heart transplant operations began (Christiaan Barnard,
South Africa).
1970-1990
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Drugs to treat ulcers, asthma and leukaemia developed.
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Prostaglandins discovered.
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Morphine-like substances produced by the brain (enkephalins)
discovered.
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Transplantation rejection understood.
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Drugs to suppress rejection of transplanted organs
developed.
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First lung transplant operation performed.
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First test-tube baby born.
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Better understanding of the basis of memory.
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CAT scanning for improved diagnosis.
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Greatly improved life-support systems for premature
babies.
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Vaccines for certain types of meningitis developed.
1990s
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Genetic therapy for cystic fibrosis began.
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Electronic implants for treatment of deafness and muscle
paralysis.
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First artificial lung implant.
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The genetic basis of programmed cell death is clarified,
with implications for the treatment of several diseases, including
Alzheimer's, rheumatoid arthritis, strokes, traumatic brain injury
and certain types of cancer.
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The first animal (a sheep) cloned from adult cells.
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After natural mating, the first cloned sheep gave birth
to her first lamb.
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