Pigs, or swine, are
increasingly appreciated as excellent models for medical
research. Among their advantages as research models are
their short reproductive cycle, ease of breeding, large
litter size, diversity of gene pool and early maturity. In
addition, pigs and humans are similar in many aspects of
both infant and adult anatomy, physiology, biochemistry,
pathology and pharmacology.
Because there is no
placental transfer of antibodies to the developing pig
fetus, newborn piglets lack maternal antibodies, making them
good for studies of the mechanisms of immunity.

The hairless, abdominal skin of the pig has an almost human
texture, permeability and thickness, affording researchers
an excellent model for dermal research. Pigs were
used, for example, to develop and test the patches which
travelers wear on the skin to prevent motion
sickness.
Many treatments and drugs
for skin diseases, including therapy
for severe burns, have been developed in pigs.
Research into how wounds
heal has also benefited from the contributions of swine,
making them invaluable tools for researchers in plastic
and reconstructive surgery, as well as other areas.
Swine have been used
extensively in nutrition
studies. Because they can suffer from gastric
ulcers, they are widely used in ulcer research.
Pigs are also useful to
medical researchers studying cardiovascular
problems. In general, the cardiovascular and
integumentary systems of miniature swine are more
biologically similar to humans than those of any other
animal. This similarity is most marked in the anatomy and
physiology of the heart, and pigs have been useful in models
of cardiac
surgery, including heart
transplantation and
pacemaker studies.
Their role in the testing
of cardiovascular
drug treatments is
well documented, and they can be good models for studies of stress and
its relation to such disorders as hypertension.
Pigs have shed light on the relationship between exercise
and coronary physiology and health.
As early as 1775, pigs were
shown to develop atherosclerosis as
a natural part of aging. Normal, healthy swine are known to
develop spontaneous atherosclerotic plaque similar to that
seen in humans. This disorder develops more rapidly in pigs
than in humans and can be increased with feed containing
high levels of fat and cholesterol.
This makes them a model of
choice for studying
the role of diet in development of atherosclerosis. It
is studies like these that have taught Americans of all ages
to reconsider their dietary habits in order to prevent heart
disease.