The fight against disease and injury has advanced swiftly on several fronts, ranging from the latest technological advances to recently rediscovered alternative approaches. Among the beneficiaries are some who never say "thank you" and cannot pay. PNS associate editor Walter Truett Anderson, author of "Evolution Isn't What It Used To Be" (W.H. Freeman), is a political scientist who writes widely on technology and global governance.

Some get the best that new medical high technology has to offer -- kidney dialysis, gene therapy, computer-aided-design prosthetic joints, even organ transplants. Others have their illnesses and injuries treated by alternative methods -- acupuncture, massage, herbal remedies, homeopathy.

That describes life in the medical fast lane for those who can afford it -- meaning, of course, those human beings. But, with relatively little fanfare, it is also becoming a description of life for a growing number of cats, dogs, prize farm animals, racehorses, and miscellaneous other birds and beasts. Because, as the human species marches forward into the bewildering landscape of twenty-first century medicine, their pets and livestock are not far behind.

Consider a recent report from the University of California at Davis -- the nation's number one veterinary school, a sort of Harvard for Holsteins -- where no effort is spared to bring the advantages of medical science to the animal kingdom. It includes photographs of a doctor doing a brain tumor biopsy on a dog, a yellow cat relaxing during kidney dialysis, a nurse holding a stethoscope to the feathered breast of a tropical bird.

The report itself details a wide range of high-tech treatments including not only dialysis but organ transplant operations, intensive neonatal care -- including intravenous food and antibiotics, oxygen-supplying nose tubes -- for premature foals, prosthetic implants for dogs with hip dysplasia, ultrasonic eye surgery for animals with cataracts, gastrointestinal and respiratory tract surgery on birds, pacemakers for dogs with heart trouble -- and radiation therapy, chemotherapy and even innovative gene therapy for dogs with brain tumors.

Most of these procedures are expensive, of course, and some of the animal owners are extremely wealthy. The report mentions a Saudi princess who had her cat flown in for treatment of kidney problems. But some owners are people of modest means willing to make a sacrifice for their pets, and others are animal breeders who find the investment -- in the care of a prematurely-born thoroughbred foal, for example -- economically justified.

Where New Age sensibilities are more prevalent, animal owners are turning in large numbers to other kinds of healing. Ailing or unhappy dogs and cats are commonly treated with acupuncture, massage, chiropractic adjustment, homeopathy, even aroma therapy -- spraying supposedly curative scents such as eucalyptus or lavender into the air around the places where they sleep. Water bowls are likely to be laced with herbal remedies.

Alternative veterinary medicine, as it's called, is certainly not confined to California. It has become a recognized international profession, with its own associations --- the American Holistic Veterinary Medical Association, the International Veterinary Acupuncture Society -- complete with conventions, journals, newsletters and web sites.

And of course it has become controversial -- with arguments, accusations and counter-accusations of quackery, self-interest and closed-mindedness very like those that rage through the human branches of medicine.

There is not only conflict between licensed veterinarians and unlicensed "practitioners" of alternative therapies, but also within establishment veterinary medicine itself. Two years ago the American Veterinary Medical Association published guidelines that some members found to be entirely too permissive. These vets, suspecting that the Association was taking a liberal attitude so members could start using alternative methods and thus keep non-licensed competitors from stealing their business, formed a Task Force on Veterinary Pseudoscience to press for more rigorous standards.

So it goes -- and is likely to keep going. Science-based researchers at centers like UC Davis will continue adapting all the discoveries of modern medicine to veterinary practice, alternative practitioners will continue to flourish as long as there are people who believe in the value of what they are doing, and peacemakers in the middle will continue to search for ways to combine the best of both worlds.

And all of us who own pets or livestock will continue to find that caring for them -- like caring for ourselves -- is an increasingly complicated affair, bringing more options and choices than we know what to do with.