In the past 35 years, the health of  housecats has been improved to such a degree that their life expectancies have increased 6-8 years, allowing indoor cats to live up to 20 years.

 

This improvement in feline health has been brought about by better nutrition; new and improved diagnostic and surgical procedures; treatments for such conditions as tumors, pneumonia, and skin disorders; and vaccines against life-threatening diseases such as distemper and leukemia. All of these improvements in the health of cats were made possible by medical research.

 

Due to the similarity in the function of cats' cells, blood, and other tissues to that of humans, cats also share many diseases with humans. For this reason, they have been showing the way to new medical knowledge for many years. Cats have been used in learning studies, becoming subjects for laboratory tests of learning ability. The results of these tests have been applied to human educational practices.

 

In the area of brain research, cats have been very important research models. In fact, more is known about the anatomy of the cat's sensory systems (for example, the skin, visual and hearing systems) than those of any other animal.

 

The field of neuroscience is very much indebted to cats for the contributions they have made. As neuroscientists developed reliable anaesthetic methods and delicate instruments to examine the nervous system, cats were used to study a variety of neurological problems, such as epilepsy, deafness, vision problems and others.

The Nobel Prize-winning work of David Hubel, for instance, made important contributions to the knowledge of vision by studying the development and function of the visual system in cats. Due to this research, it is known that human beings are not born with a fully developed visual system, and that proper development of vision requires stimulation of the visual neurons.

 

Cats, too, have been useful models for research on aging. Their relatively long life span compared with mice and rats makes it possible to observe the slower and more subtle effects of aging. Observational studies with well-cared-for pet cats, who are known to reach the age of 16-20 years, are useful to study aging processes which do not require surgical intervention.

 

Cats are very important subjects in cancer research. Leukemia is perhaps the most infamous of the diseases shared by cats and people. In cats, it is caused by an AIDS-like retrovirus. A recently discovered vaccine against feline leukemia may act as a model for an AIDS vaccine. Mammary cancer is also common in the cat, and many features of feline mammary cancer resemble the human breast cancer which, among the human cancers, is the greatest killer of women.

 

Toxoplasmosis is a disease in cats caused by a parasite which reproduces in the cat's intestine. Many thousands of human infants are born every year with this disease, and many of these infants have damage which requires permanent hospitalization.  Research in cats is being conducted to develop treatment and preventive measures against this disease.

 

Since 1898, cats have also contributed to the study of emotion, cardiac disease, spinal cord injury, cataract surgery, glaucoma, lupus, diabetes, spina bifida and more. Because these and the above diseases are common in cats, these animals stand to benefit greatly from the medical research advances which they make possible.

 

Cats and AIDS - The Circle Closes: Researchers have been working on viral diseases of cats for over 35 years. In the 1960's, many animal diseases, including cancer, were known to be caused by viruses, but few similar diseases had been identified in humans. Among the classes of viruses which were studied were the retroviruses, one type of which causes feline leukemia.   In the late 1970's, the emphasis in human cancer research turned to carcinogens and funds for research into viral causes of cancer became scarce. That is, until the AIDS epidemic became known to health officials and to the public.   AIDS had all the hallmarks of retrovirus diseases such as feline leukemia, so scientists searching for the cause knew where to begin looking. All of the earlier work on retroviruses in animals made it possible to identify the AIDS virus.   When the AIDS virus was identified, it turned out to be from a different subfamily of viruses known as lenti viruses. These viruses cause chronic disease syndromes in livestock, but had not previously been thought to be important in human disease.   As a result of the AIDS epidemic, researchers began s tudying cats that had AIDS-like symptoms, but had tested negative for the feline leukemia virus. Several years ago, the first "AIDS" virus in cats (T-lymphotropic lenti virus) was reported.   While cats cannot transmit AIDS to humans, this virus is genetically similar to the human AIDS virus, and the pathogenesis of the feline disease is remarkably similar to human AIDS. Cats develop chronic infections of the skin, mouth, respiratory and intestinal tracts, and are susceptible to opportunistic infections, as well as some neurological diseases. Eventually their immune system completely breaks down and they cannot survive.   Cats naturally infected with this lenti virus are being used as models to study the pathenogenesis of AIDS and to develop effective drug therapies for both humans and cats.   The early work done on feline leukemia helped with the understanding of AIDS, and the AIDS research going on today has helped researchers to better understand the feline equivalent of the disease. In the end, both people and cats benefit from the knowledge gained.