Animal chiropractic care focuses on biomechanical disorders of the musculoskeletal system, principally the spine. Treatment typically involves manual manipulation of the joints and soft tissue, measures designed to promote the body’s natural healing powers.

“We’re getting more calls about this from animal owners, and from veterinarians as well, but there’s not much hard data available,’’ Smith said. The official position of the group, a nonprofit association representing 80,000 veterinarians nationwide, he added, is, “if an animal can benefit from it, the veterinarian has the right to offer that treatment option. But in all cases a veterinarian should be part of any diagnosis and treatment plan.’’

Nevertheless, Dr. Craig Smith, a veterinary association staff consultant, said there is strong anecdotal evidence that nontraditional treatments, and specifically chiropractic care, are gaining in acceptance among pet owners and vets alike — even though the association would like to see more rigorous study to determine whether they are indeed both safe and effective.

Regarding it and other so-called alternative therapies such as acupuncture and homeopathy, American Veterinary Medical Association guidelines reflect this division of opinion. While its membership is “open to their consideration’’ in prescribing such treatments, the guidelines say, veterinarians “should exercise caution’’ in pursuing treatment options that may claim to be safe and effective but have yet to be proven so by scientific method.

Animal chiropractic does not lack for skeptics. As is the case with human patients, chiropractic care is frequently viewed by the medical establishment as unscientifically proven, if not outright quackery.

“Most horses, like dogs, will let me do whatever I need to do to help them,’’ Cooper said as he worked. “They’ll see me coming and go, ‘Oh, I’m going to loosen up and feel better.’ ’’

A growing number of horses and dogs — along with cats, goats, birds, zoo animals, and other creatures great and small — are seeing chiropractors as part of a comprehensive treatment plan, one that might otherwise rely upon expensive surgery and potent medication to relieve chronic discomfort, according to veterinarians and animal chiropractic specialists.

Six months ago, according to Jude’s owner, Abby Clutz, the horse would pin back his ears and “explode with discomfort’’ when ridden. Now, with monthly chiropractic treatments, he is being ridden in equestrian competitions and is off pain medication.

Jude has chronic shoulder tightness and back pain, but he barely flinched as Cooper worked his way along the musculoskeletal system, ending with an “adjustment’’ thrust to Jude’s right carpal joint.

WESTON — Both hands planted firmly on Jude’s hindquarters, Matthew Cooper applied pressure to the horse’s pelvic region, a chiropractic technique known as motion palpation. Jude, a 1,200-pound retired racehorse bearing the legendary Seabiscuit’s bloodline, is fully capable of kicking Cooper into a barn wall, but stood motionless.

Ten years ago, alternative or “complementary’’ therapies were rarely mentioned in veterinary schools, said Dr. Alicia Karas, an anesthesiologist with Tufts University’s Cummings School of Veterinary Medicine. That has changed dramatically, Karas said, with many schools now offering courses in nontraditional therapies and humans looking at their own health more holistically, then applying that perspective to their pets. Karas herself is studying acupuncture.

Tufts does not include such courses in its core curriculum, said associate dean for academic affairs Dr. Angeline Warner. But the school does make training available through elective courses, continuing education programs, and outside speakers in what amounts to “a slow but steady increase’’ in studying alternative treatment modalities at Tufts.

The Association of American Veterinary Colleges, an organization representing 28 veterinary teaching institutions, does not track the number of courses or faculty members offering training in chiropractic care, said associate executive director Dr. Ted Mashima. But, he said, “our general sense is that these course offerings are on the increase.’’

Ten animal chiropractic specialists — certified by the 750-member American Veterinary Chiropractic Association — practice in Massachusetts. Another five or six are licensed by the organization but are not dues-paying members, according to Dr. Randy Caviness, a Bolton veterinarian who is certified in chiropractic care.

Cooper, based in Wayland, sees human patients four days a week, house pets and horses two days. Like many others in his hybrid profession, Cooper worked on humans for years before branching out to other species, in his case four years ago.

The convergence of the two professions, veterinary care and chiropractic, is not new; it began about a century ago before undergoing a revival in the 1980s, according to Cooper and others. Lately, however, it’s become less of a curiosity — your border collie gets what kind of treatment? — and more a commonplace treatment option.

In many cases, practitioners say, an owner might be advised to have an aging pet or farm animal euthanized. Chiropractic care thus becomes his or her last resort.

“There’s this stigma of the little fluff ball some woman brings to her own chiropractor,’’ Cooper said. “But when you think about what we do, people really get it.’’ By alleviating joint and muscle problems that impede movement, he said, not only can he improve an animal’s quality of life, he may prolong life, too. “For animals, freedom of movement is everything,’’ he said.

Dr. Gene Giggleman, president of the chiropractic association, said it is no surprise that the appetite for alternative health care has spilled over to veterinary medicine, whether the patients are race horses and show dogs or beloved house pets with arthritis issues.