What is veterinary medicine?

Science and Profession

Animals become sick, get injured, or fail to perform as well as they should, just
as humans do. Humans, however, have developed a much more sophisticated medical
expertise about themselves than they have about the wide variety of other animals.
The basics of this medical knowledge apply to other animals, but the physiological
differences of each of the many kinds of animal species preclude the application
of human medical care. Much of veterinary knowledge has traditionally been
concerned with a few common species, such as cats, dogs, cattle, sheep, goats,
swine, horses, and some birds. Other species are receiving increasing attention,
however, and their medical needs are becoming more widely acknowledged and better
understood.

Most of the medical fields concerned with human health apply to veterinary health
practice as well, including anatomy, anesthesiology and pharmacology,
biochemistry, cardiovascular medicine, cell biology, dental medicine, dermatology,
disease pathology, emergency and critical care, endocrinology, epidemiology,
gastroenterology, genetics, geriatric medicine, hematology, immunology, internal
medicine, microbiology, nephrology and renal medicine, neurology, obstetrics,
oncology, ophthalmology, orthopedics, osteopathic medicine, otorhinolaryngology,
physiology, psychiatry, surgery, and urology. There has been much progress in the
veterinary applications of these fields. There has also been considerable progress
in the application of the expertise, techniques, and equipment used in these
fields to an increasingly wide variety of animal species. This development is
attributable to both an improved knowledge of and interest in these other species
and a growing ethical concern for this wider range of species.

Not only have humans become more knowledgeable about how to care for less common
domestic and wild animals, it has also become more acceptable to do so. As a
result, veterinarians have become involved with a much wider range
of employment opportunities in government, business, universities, and zoological
parks, although most are still in private practice and dealing with farm
livestock, horses, cats, and dogs. In addition, veterinarians are also working in
a wider range of locations, including clinics, research laboratories, farms,
zoological parks, and the wild. There are also more employment opportunities for
veterinary
technicians, paraprofessionals who assist the veterinarian or
who carry out certain veterinary duties when the veterinarian is not
available.

Veterinary medicine is both a distinct medical field and an extension of human
medical fields. It deals with species quite different from humans, the degree of
difference ranging from slight (such as with primates) to great (such as with
birds, reptiles, amphibians, and fish). While medical doctors deals with only one
species, veterinarians are concerned with a multitude of species. Therefore,
medical doctors tend to specialize in a particular field, while veterinarians tend
to specialize in particular kinds of animals. There are some similarities and many
differences between human medicine and veterinary medicine, with one common ground
being zoonoses, those diseases that can be transmitted between
humans and other animals. These degrees of similarity and difference among species
are a primary concern for the veterinarian and are one of the things that make
veterinary medicine such an interesting subject.

Most veterinarians perform routine clinical work, both in the office and in the
field, dealing with farm livestock, domestic pets, and racing horses and dogs.
However, some are involved in other kinds of work. Veterinarians may work with
exotic pets; exotic livestock, such as on ostrich or alligator farms; zoological
park and aquarium animals; or laboratory animals. They may maintain healthy game
herds and flocks, such as deer and turkeys; translocate wild animals from one area
to another; work with teams doing scientific research that involves animals; help
with efforts to save endangered species, either in the wild
or in captivity; work with beached porpoises, whales, and other sea mammals; or
advise government agencies concerned with animal-welfare issues.

In addition to treating sick and injured animals, veterinary medicine involves advising on preventive measures, making routine observations of individual animals or groups of animals, evaluating herd management, assessing environmental and housing conditions, assisting with births, and performing necropsies. Veterinarians working with laboratory animals, zoological park animals, native game species, or endangered species may also provide advice on reducing stress; assisting with propagation strategies, including various artificial propagation techniques; tranquilization; translocation techniques; the gathering of tissue samples; and other animal-welfare matters.

The control of epidemic diseases in farm livestock or native wildlife is also
carried out by veterinarians. Diseases that may be introduced by imported animals,
particularly exotic species, are of interest as well. For example, parrots
imported for the pet trade are capable of transmitting diseases that could affect
poultry, as are migrating native bird species. Imported exotic hoofstock can
introduce diseases that could affect farm livestock, as could the importation of
farm livestock from already infested areas.

For these reasons, species similar to those on farms and ranches, usually birds and hoofstock, are subjected to medical quarantines and other medical restrictions. The transfer of animals or animal products from one country to another by private citizens is strictly controlled. Diseases that can be passed to humans by animals, particularly those sold as pets, are closely monitored. Another problem involving both medical doctors and veterinarians is those diseases that can be passed from native wild animals to humans, either directly or through other host species, such as insects.

Veterinarians working in the field on medical problems involving native wildlife, imported exotic species, or endangered species are often on their own, working at remote sites and frequently carrying their clinics on their backs. Improvisation, creativity, and adventure are typically part of their practice.

In summary, while the application of veterinary medicine involves the same kinds of medical fields as those used in human medicine, the methods, techniques, equipment, medicines, and treatments are different. The degree of difference depends on the species and the area of operation, which ranges from urban clinics to rural farms to the wilds of remote wilderness areas.

Diagnostic and Treatment Techniques

Most medical fields are much better developed for use with humans than with animals, because humans know so much more about themselves than they do about the other animal species. Humans constitute only one of innumerable species—one that has been studied in depth for quite some time. Unlike human medicine, veterinary medicine is concerned with many animal species, each of which has its own physiological parameters. In addition, different categories of animals—mammals, birds, reptiles, amphibians, or fish—have significantly different body systems. These different categories and species have to be treated differently when determining whether an animal is normal and healthy and when prescribing treatment for a sick animal.

The best-understood groups of animals are the ones that have been of concern to
the veterinary profession for the longest period of time, namely farm livestock
and pets. More recently, other groups have received attention, including animals
in zoological parks, laboratory animals, native wildlife, and endangered species.
As ethical concerns have extended beyond the human race, more concern has been
shown for the health of all animal species. There remains much to learn about the
many species that are not dealt with on a regular basis by veterinarians.

The diagnosis and treatment of an illness or injury depend on the kind of animal
being examined. Since the animal cannot tell its owner or the veterinarian what is
wrong, it is up to the veterinarian to discover this information. The diagnosis is
therefore particularly important. First, the veterinarian must analyze any
abnormality. On a clinical level, this means a general physical examination, a
special examination of the suspect system or organ, a special examination of the
problem area, and a medical history, as well as laboratory tests and a comparison
with peer performance standards. Second, if applicable, the veterinarian must
analyze the pattern of occurrence of the abnormality in the herd; this process
includes an epidemiological examination and an evaluation of general management,
environmental factors, time of year, nutritional status, and genetics. The
veterinarian then categorizes and defines the abnormality, prescribes a treatment,
follows up on the treatment, and advises the owner on prevention.

The first step in providing care is knowing when an animal is sick. An injury is easier to detect, but it may still be difficult to determine the extent of the injury. Lack of performance may or may not be a medical problem. It is easier to determine when an illness is present in animals with which humans are very familiar, such as pets, horses, or livestock. It becomes more difficult with other mammals and birds, and especially with fish, reptiles, and amphibians.

The species of the animal being evaluated must be known, along with the
physiological parameters for that species. The medical history of the
individual—and, if applicable, the other individuals with which it is associated,
such as a herd—is also necessary. A clinical examination is then used to determine
the current medical situation, supplemented by a laboratory examination and an
epidemiological examination. These examinations include consideration of past
diseases and treatments, nutrition, behavior, general appearance, skin condition,
voice, eating habits, defecation and urination, posture, and gait; the inspection
of specific body regions; a physical examination, including taking the animal's
temperature and pulse; consideration of environmental factors, such as housing,
source of water supply, sanitation, and chemical contaminants; and laboratory
tests on specimen samples from the animal and the environment.

Based on this information, a diagnosis is made and a treatment is prescribed. The
diagnosis should provide information on the disease or injury, the etiology of the
disease, and the clinical manifestation—that is, the severity or extensiveness—of
the disease. The treatment may involve additional care, surgery, medication, a
change in diet, or a change in the animal’s environment.

Follow-up on the treatment may also be necessary, as well as continued monitoring
and reexamination. Medicines can have side effects, and multiple medicines can
have synergistic effects. Another problem is that animals tend to care for
themselves by licking, pulling at bandages, and other behaviors that can undo what
the veterinarian has done. Also, animals are not able to say whether they are
feeling better, although this can often be determined by observing the animal’s
return to normal behavior.

Preventive health care is as important for animals as it is for humans. This type
of care may involve vaccination shots, pills, proper nutrition,
dental care, reduction of stress, exercise, sanitation and proper housing, the
quarantine of exotic species, or simply observation of behavior.

Low performance may be a medical problem, but is difficult to detect because the
problem tends to be a subclinical disease. The performance of livestock and racing
animals may require the attention of veterinarians. The efficient performance of
livestock is economically important to the farmer, and an assessment of a herd’s
productivity is usually done by comparing its performance with a standard that is
based on known performances of peer herds. Productivity can have several meanings,
including reproductive efficiency, the amount of milk or meat produced per animal
or per hectare, calf survival rate, longevity, and acceptability or quality of the
milk or meat at market. Low performance might be caused by a number of factors,
such as inadequate nutrition, poor genetic inheritance, improper housing, stress,
lack of herd-management expertise, subclinical diseases, physiological
abnormalities, or anatomical problems.

Although some veterinarians specialize in a particular medical field, for the most
part, a veterinarian has to be familiar with all medical fields in order to treat
an animal. While these fields are basically the same whether one is treating a
human or an animal, veterinary medicine is complicated by the fact that each
species has different body structures and physiological parameters. Also,
different equipment and techniques are necessary in applying these medical fields
to animals. For example, the principles of anesthesiology are well understood, but
applying anesthesia to a human is not the same as applying it to a dog, a horse,
or an elephant. The gases and doses used, the equipment needed, and the procedures
performed must be tailored to the particular kind of animal being treated.

Most veterinary work is carried out in the clinic, particularly small-animal practice, which usually involves cats, dogs, and other common pets. Large-animal practice, typically involving farm livestock and horses, is often done at specially designed on-site areas at a farm or ranch. Veterinary schools have both small-animal and large-animal clinics. While small animals are easily handled, large animals need pens, squeeze cages, tilting tables (able to tilt from a vertical position, in which the animal is strapped onto it, to a horizontal position), and other equipment to restrain them during the examination. Large-animal veterinarians working on a farm or ranch also use veterinary vehicles that are stocked with whatever the veterinarian normally needs. In rural areas, the animals requiring care tend to be too far away from the clinic for veterinarians to repeatedly return to the clinic for supplies while making rounds, so their vehicles are specially adapted as mobile clinics, either by the veterinarians themselves or by commercial companies.

Perspective and Prospects

Animal
domestication developed around 8000 BCE. With humankind’s
increasing dependency on domestic animals, it became necessary to care for their
medical needs. The Code of Hammurabi, a legal code from
Babylonia that dates to the eighteenth century BCE, mentions payments to animal
doctors if they successfully care for an animal and punishment if they are not
successful. Papyri from ancient Egypt contain the oldest known veterinary
prescriptions (ca. 1900 BCE). The first veterinarian known by name was from India
(ca. 1800 BCE). It was also in India that the first known animal hospitals were
established, around 250 BCE. The Aztecs of ancient America also had animal doctors
for the large royal animal collections. Ancient civilizations treated diseases
with herbs and rituals; some surgical procedures were performed, and some injuries
were treated. Medical instruments were crude, and care was based on magic and
folklore. This was not unusual during a time when medicine, science, and religion
were integrated into one limited body of knowledge. The fact that an effort was
made to care for animals indicates their importance to these early societies.

While medical knowledge increased in ancient China and Greece, veterinary
knowledge did not. In the Roman and medieval periods, practitioners simply
compiled and transcribed what had already been done. Nevertheless, the advances
made in medical knowledge—for example, the determination that diseases have
natural rather than divine causes—would affect veterinary medicine as well.

The Renaissance brought about a renewed interest in many areas of study, including
veterinary medicine. In particular, there was concern about farm livestock and
horses because of their increasing economic importance to society. In addition,
much of the medical research conducted during this time was done with animals.
Advances in veterinary medicine at first coincided with those in medicine in
general but were eventually made for their own sake. The first short-lived
veterinary schools appeared in Spain around 1490, and the first modern ones
appeared in Europe during the eighteenth century. It was not until the nineteenth
century, however, that methodological observation and examination became the
foundation for diagnoses and veterinary medicine passed from the common
practitioner to the academic or professional practitioner.

One significant effect of the growth of veterinary medicine and its acceptance by the general public has been the concept of animal rights, which has increased the provision of medical care to pets, exotic animals, and native wildlife. At the same time, veterinary knowledge has been extended to amphibians, reptiles, and fish, as well as to a larger array of birds and mammals.

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